The Ottawa Sewer Explosions

29 May 1929 and 28 January 1931

Almost ninety years ago, the City of Ottawa was rocked by two series of sewer explosions that occurred twenty months apart. The first happened on 29 May 1929, and the second on 28 January 1931. Both hit the same areas of town—Sandy Hill, Vanier (then called Eastview) and New Edinburgh—and caused extensive damage. There was also one fatality in the first set of blasts; many were injured. Despite three inquiries, the exact cause of the explosions was never conclusively determined though leaking illuminating gas used for lighting was believed to have been the culprit. However, a lengthy law suit launched by the City against the Ottawa Gas Company to cover the costs of the second explosions failed.

Sewer 1929 29 May OEJournal

Headline, The Ottawa Evening Journal, 29 May 1929


The 1929 explosions began shortly before noon on 29 May in the block bounded by Cartier, Frank, Waverely and Elgin Streets in the Golden Triangle neighbourhood of Centre Town, blowing out manhole covers in the area.  The resulting fire ignited gas inside the main sewer line running eastward under the Rideau Canal, causing shaking, rumbling and venting through manholes on Templeton Avenue, Henderson Avenue and Nelson Streets in Sandy Hill, before travelling down St Patrick Street and into New Edinburgh on the other side of the Rideau River along Crichton, MacKay and John Streets to the sewage outlet into the Ottawa River. There were also a number of smaller blasts in the Eastview and Clarkstown areas (Vanier) between Montreal Road and Beechwood Avenue.

At least twenty-eight manhole covers were blown in the air, some thirty to forty feet, before crashing to the ground. Clouds of smoke and vivid tongues of flame were reported emanating from the manholes. Mrs Hannah Henderson, age 73, of 37 Templeton Avenue was killed when flames shot out of her kitchen sinkhole and ignited her clothes. Although she managed to flee her home, she later succumbed to her injuries in hospital. Around the corner at 192 Henderson Avenue, Miss Lilian Pettapiece, age 20, escaped a similar house fire with serious burns. She had been in her cellar choosing potatoes for lunch when she was enveloped by flames that shot out of a sewer connection. Despite choking fumes, she managed to stumble up the stairs to the outside where she was rescued. Many others were injured by flying glass blown from windows. The home of Captain Sam Blackler of the Ottawa Fire Department at 211 Henderson Avenue was rocked from its foundations by the force of a blast and was gutted by fire. Fortunately, nobody was hurt. Mrs Blackler suffered a narrow escape, however. She had just walked out of the kitchen a minute before it was wrecked. An apartment building at the corner of Somerset Street East and Chapel Street, which housed a grocery on the ground floor, also suffered serious structural damage. In New Edinburgh, St Martin’s Anglican Chapel on John Street was destroyed. In total, the sewer explosion caused roughly $40,000 in property damage.

Sewer explosion 30-5-1929 TOJ

The home of Captain Sam Blackler of the  Ottawa Fire Department at 211 Henderson Street after the sewer explosion, 29 May 1929, The Ottawa Evening Journal, 30 May 1929.

Ottawa’s mayor Arthur Ellis was convinced that the explosions were not due either “to defects in the city sewer,” or to sewer gas (a mixture of hydrogen sulphide and other gases). Municipal leaders commissioned John Campbell from the Edison Illuminating Company of Boston to conduct an inquiry into the disaster. Campbell concluded that the exact nature of the gases that exploded might never be known as no tests were performed on gas in the sewers prior to the explosion. However, he pointed to two possibilities: i) gasoline vapours due to the improper disposal of gasoline by homeowners, leakages from the growing number of service stations in the area, and waste from dry-cleaners, or ii) a leak from a gas main. He noted that the Ottawa Gas Company had been digging for leaks prior to and during the day of the explosion. He added that the sewer explosion need not have been the result of a single big leak but could have been due to a number of small ones. While not specifically pointing the finger at illuminating gas, he added that the lack of soot deposits and the nature of the fire suggested a gas lighter than air was responsible; gasoline vapours are three times heavier than air whereas illuminating gas is half as heavy as air. Campbell was of the view that the exact point of ignition was in the Frank-Cartier Streets area. However, what caused the ignition would never be known. He postulated it could have been a lighted match, the backfire of an automobile, or a spark from a trolley wheel.

Rather than lay blame, which he argued was outside of the remit of his report, Campbell made a number of recommendations. These included the prompt investigation of complaints about gas smells (complaints prior to the explosion were apparently not investigate with any degree of diligence), the regulation of the sale of gasoline to homeowners, a prohibition on disposing of volatile fluids in the sewers, and the inspection of gasoline service stations. He also recommended the construction of ventilation stacks with fans to help dissipate volatile vapours in the sewers, and the hiring of additional staff by the City to keep up to date in the matter of inspecting, testing and the keeping of records.

The second series of sewer explosions began at roughly 4.30 pm on 29 January 1931 just two days after the City had made its last payment for damages from the previous explosion to St Martin’s Chapel. As was the case in 1929, it started in the Golden Triangle area of Centre Town, this time at the corner of Lewis and Robert Streets. The explosion was accidently ignited by a plumber’s assistant who was investigating the source of a foul odour in the basement of a home.  Apparently, a spark from a trowel he was using ignited gas emanating from the sewer.

Sewer, 29 May 1931 Journal

Headline, The Ottawa Evening Journal, 29 January 1931

Replicating in many ways the 1929 disaster, the blast rumbled down the main sewer line blowing up manhole covers in Sandy Hill along Templeton Street, Nelson Street and Somerset Street East, through Strathcona Park, before travelling along the east bank of the Rideau River to John Street in New Edinburgh. As in 1929, twenty-eight manholes covers were sent flying, sixteen of which featured in the earlier disaster. The damage sustained to the sewer system was severe. There were at least four breaks. The 78-inch main sewer on the Eastview (Vanier) side of the Cummings Bridge, which carried much of the sewage from the eastern portions of the city to the outfall at John Street into the Ottawa River, was fractured. Another 54-inch sewer running from Ottawa South along the west bank of the Rideau River was also ruptured near the Strathcona Hospital. With these breaks, sewage backed up into Sandy Hill. To prevent the flooding of homes, the City excavated at two points, one on Somerset Street and the other near the Isolation Hospital, and pumped the sewer water into the Rideau River. In total, more than a mile of sewer was wrecked with damage placed at almost $400,000, roughly ten times that of the earlier 1929 sewer explosion.

Fortuitously, this time no lives were lost. There were, however, a number of close calls. Twelve-year old Munroe Dingwall of 138 Goulburn Avenue was skiing on Somerset Street East with friends when a manhole cover blew up beside him. The lad was lifted into the air, skis and all, and deposited stunned but unhurt into a snowbank. Poor Miss Pettapiece, who suffered grievous injuries in the 1929 explosions, was on a bus near home when a manhole exploded. She collapsed and had to be treated for shock. A number of children were skating on the Sandy Hill rink on Nelson Street between Somerset East and Templeton Street when gaping holes appeared in the streets around the rink. The children were unharmed and taken to safety.

The City launched two inquiries. The first by consulting engineers Gore, Naismith and Storrie of Toronto concluded that gasoline and illuminating gas were “reasonably probable” causes. Of the two possibilities, the engineers favoured illuminating gas on the grounds that there was little evidence of flames or black smoke emanating from the explosions that would have been characteristic of a gasoline fire. Also, they viewed it as improbable for a perfect mix of gasoline vapour and air to have occurred. But, in the absence of all data and an analysis of sewer air before the explosions, they refrained from given an opinion regarding the source of the responsible gas.

They did, however, make a number of recommendations. First, they recommended that there be a judicial inquiry under oath so that all relevant records and other information pertinent to an inquiry could be obtained. Second, they argued that Ottawa’s method of ventilating sewers was dangerous and obsolete. They recommended the construction of more ventilating shafts, the opening of manhole covers, and the checking of home drains attached to the sewers. Apparently, many were not properly trapped. Other recommendations included the regulation and supervision of establishments using flammable gases or liquids, a regular inspection of sewers every six months, and the construction of sewage treatment plants.

A second committee chaired by Dr Alfred E. MacIntyre, a retired former chief of the Explosives Branch of the Dominion Government, focused on the causes of the blasts. MacIntyre had also consulted on the Campbell Report into the earlier 1929 explosion. He was of the opinion that illuminating gas had been the cause of both explosions. His report concluded that “gas had adventitiously entered the soil, drainpipes, sewer, etc. from defects within the gas distributing system of the Ottawa Gas Company.” Needless to say, the Gas Company came up with the opposite conclusion averring “that gas is the last thing that could be considered in connection with the recent sewer explosions.”

MacIntyre was pretty damming of the City as well. His report said the City had made no attempt to investigate the 1929 explosion, and that the investigations of complaints about fouls smells from residents were “neither informative nor satisfactory.” He contended that members of the inspectorial staff “had neither developed their powers of observation nor acquired sufficient qualifications and knowledge to discriminate or determine the actual condition of hazards, nor a conception of fitting methods of relief, conditions largely attributable to lack of instruction and direction.” MacIntyre also criticized the City for improper ventilation of the sewers, a charge to which the City responded by saying that it was not responsible for keeping sewers free of volatile gases that enter the sewers through the negligence of another company.

On release of MacIntyre’s report, the Board of Control suspended Mr W. F. M. Bryce, the engineer responsible for Ottawa’s sewers for negligence in not taking adequate measures to ensure that the sewers were kept free from dangerous gases. Bryce subsequently resigned. Earlier in the year, Mr A.F. Macallum, the Commissioner of Works, had also resigned, having been held responsible for not taking sufficient precautionary measures to avoid a repetition of the 1929 blasts.

At City Hall, the two investigations into the 1931 explosions set the proverbial cat among the municipal pigeons. Amidst a rancorous debate, City Council defeated on a split 11-11 decision a motion supported by Mayor Allen for a judicial inquiry into the explosion as recommended by the consulting engineers from Toronto. A motion for an independent inquiry into the conduct of Mr Bryce, the sewer engineer, was also defeated on a close 11-10 decision. Subsequently, however, the City launched a law suit against the Ottawa Gas Company in the amount of $376,000 for damages resulting from the 1931 blasts. Despite the testimony of roughly 100 witnesses, the evidence provided by the two inquiries into the sewer explosions, and an admission of the Ottawa Gas Company that its pipes and gas mains had not been inspected since they were installed, the Court ruled in favour of the gas company owing to lack of evidence. After losing an appeal, the City paid the court cost of both parties.

Following the inquiries, the City took steps to improve ventilation in the sewers, including the establishment of another ventilation shaft in Strathcona Park. Measures were also taken to improve the investigation of complaints of sewer smells by residents through the establishment of a complaints bureau. In the end, only Mr Macallum, the former Commissioner of Works, took the fall for the sewer disaster. Roughly eighteen months after the explosion, the Board of Control unanimously re-appointed Mr W. F. M. Bryce to his old job as sewer engineer on the curious and vague grounds that the Board had earlier requested his resignation not because members felt that he “was not fully competent, but because of the nature of the report dealing with the investigation.”


Ottawa Evening Citizen (The), 1931, “May Call Further Expert Advice On Sewer Blasts,” 29 January.

————————————-, 1931. “Experts Differ Upon Cause Of Sewer Blasts,” 10 June.

Ottawa Evening Journal (The), 1929. “City Denies Blame For Explosions, Continues Inquiry,” 30 May 1929.

————————————–, 1929. “Advises Ventilation Of Sewers, Restrictions Of Gasoline Sales And More Vigorous Inspections,” 4 October.

————————————–, 1931. “Discover Sewer Explosion Damage Much Greater,” 29 January.

————————————–, 1931, “Fourth Stack Will Be Built To Air Sewers,” 17 April.

————————————–, 1931. “Judicial Probe Under Oath Is Only Way To Learn cause Of Explosions, Says Report,” 20 April.

————————————–, 1931. “MacIntyre Report Sets It Theory Of Big Explosion,” 4 June.

————————————–, 1931. “Says Lighting Gas The Cause Of Explosions,” 10 June.

————————————–, 1931. “After Long Stormy Debate City Council Rejects More For Probe Of Sewer Blasts,” 18 August.

————————————–, 1931, “Board of Control Endorses Damage Suit For Big Sum Against Ottawa Gas Co.” 30 September.

—————————————, 1931. “Declares Pipes Only Inspected During Repairs,” 1 December.

—————————————, 1932. “Mayor States All Favorable To W.F. M. Bryce,” 17 September.

————————————–, 1932. “Open Type Tops Would Have Cleared Gases,” 25 November.

The Canal

29 May 1832

It’s no exaggeration to say that Ottawa owes it very existence to the Rideau Canal, the ribbon of water that snakes its way through the heart of the city before heading south to Lake Ontario more than 200 kilometres distant. Without this incredible feat of early nineteenth century engineering, the south shore of the Ottawa River would not have been settled where and when it was. With no Ottawa, Queen Victoria would likely have chosen Montreal, or even Kingston, as the nation’s capital, radically changing the course of Canadian history.

It all began in the War of 1812 which pitted Britain and British North America against the new, thrusting U.S. republic to the south. With the Saint Lawrence River, the principal transportation route into the interior of the continent, forming the Canadian-U.S. frontier, the movement of military and other supplies from Montreal to Kingston on Lake Ontario was a perilous enterprise. Supply vessels coming to the defence of Upper Canada were exposed to potential attack for much of the journey. Consequently, an alternative, safer route was a military necessity. In 1814, the British sent out reconnaissance missions to assess the merits of building a canal system through the Rideau Lakes system, linking Kingston to the Ottawa River which flows into the St. Lawrence at Montreal. Although interest in a canal waned at the war’s conclusion in 1815, the start of work on the Erie Canal two years later, which provided a navigable water route from New York City on the Atlantic coast to Buffalo on Lake Erie, as well as efforts by the Duke of Wellington to strengthen Canadian defences against possible future U.S. aggression, convinced British authorities to proceed with an alternative, all-Canadian route from Montreal to the Great Lakes.

Colonel By

Colonel By, Royal Engineers

In 1826, Lieutenant-Colonel John By of the Royal Engineers, who had fought under Wellington during the Peninsular War in Spain against Napoleon, was assigned the task of supervising the construction of the canal. By was given instructions to proceed with all dispatch using two companies of royal sappers and miners as well as contracted local labour. The cost of the project, based on rough-and-ready estimates made by earlier surveyors, was placed at £169,000. This number, which proved to be wildly inaccurate, was to haunt By in later years.

A ceremonial first stone to the locks at Sleigh Bay (later Entrance Bay) was laid on 16 August 1826 by the famous Arctic explorer Sir John Franklin. As well as starting construction on the initial eight locks of the canal system and two wharves, Colonel By built a hospital, barracks, a commissariat (now the Bytown museum), and storehouses. Two town sites, Upper and Lower Bytown, on either side of the canal connected by Sappers’ Bridge were also developed. Mostly English Protestant settlers lived in Upper Town. The much larger Lower Bytown was the home to working class, mostly Irish and French Catholics. The community began to swell in size as workers and their families arrived in response to the demand for skilled and unskilled labour, forming the nucleus of what later was to become Ottawa.

By established three work camps to build the canal. The first at Entrance Bay, the second at Kingston, and the third midway at Isthmus Summit, roughly where the village of Newboro is located today. In addition to the companies of sappers and miners, more than 4,000 labourers and 1,000 masons were employed, mostly during the summer months. It was a logistical nightmare to feed and equip all these people, some with families, at a time when Kingston, the largest city in Upper Canada, had less than 3,000 inhabitants. The vast majority of the workers, especially at the Kingston end, were poor immigrants from Ireland, both Roman Catholic and Protestant. Many, particularly at the Ottawa River end of the canal, were French-Canadians employed by two Lower Canadian companies, Philemon Wright and Sons of Wrightville (later Hull) and McKay and Redpath of Montreal, winners of construction contracts tendered the military.  It was a potentially combustible combination, but there was surprisingly little ethnic strife, though tempers would flare in the largely male shantytowns that grew around work sites where alcohol was widely available. Worker peace was maintained by a strong military presence.

Rideau Canal

Rideau Canal, looking into Entrance Bank, Ottawa River

It was a tough life, especially for immigrants unfamiliar with the torrid hot summers and bitter cold winters of the Ottawa Valley. Workers battled terrible conditions, labouring 14-16 hours days, six days a week, driving the canal through sparsely-populated bush country and mosquito-infested swamps. For three summers, malaria, known then as swamp fever or the ague, caused temporary work stoppages with sixty per cent of the workforce coming down with the disease; many died. In 1828, smallpox threatened Bytown. Workplace injuries also took their toll. In total, some 1,000 lives were lost, mostly from disease, in the almost six years it took to build the canal. Many were buried in unmarked graves in unconsecrated ground.

In addition to the high human cost, the financial costs of building the canal skyrocketed. Though the initial cost estimates were widely recognized as being ludicrously low, By’s decision to enlarge the size of the forty-seven masonry locks to accommodate steamboat traffic was a costly one. He was also forced to make a number of changes to the location of the canal from the original survey owing to local conditions. Furthermore, the speed of construction raised costs, as did construction setbacks; for example, the dam at Hog’s Back had to be built three times. By also had to compensate landowners whose land was expropriated for the canal. Although By’s decisions and expenses were closely scrutinized and approved by the British Army’s Ordnance Department, the British Treasury was greatly displeased when the final price tag came in at more than £800,000.

On 29 May 1832, Lieutenant-Colonel By, accompanied by his wife Ester and their two daughters, Ester and Harriet, arrived in Bytown on the maiden voyage from Kingston through the Rideau Canal. They made the five-day journey aboard the 80 foot, 12 horsepower, paddleboat steamer Pumper, rechristened the Rideau especially for the occasion. By, who must have been savouring his success, was unaware that a letter recalling him to London to explain the cost over-runs was already on its way to him. Although he was vindicated in the subsequent inquiry, By, caught in a political squabble between the army and a new, penny-pinching government, never received the recognition that was his due. He died a disappointed man in 1836 in his home in Sussex, England.

Initially, as By had hoped, the Rideau Canal became a favoured route of vessels going upriver to the Great Lakes from Montreal. But it went into decline in the late 1840s following improvements to the canals and locks on the Saint Lawrence River route which allowed larger, heavier ships to bypass the Lachine rapids. Improving political relations with the United States also undermined the Canal’s military raison d’être. The only time the waterway was used to transport troops was in 1838 when soldiers were sent to stop an invasion of “Hunter Patriots” at the Battle of the Windmill outside of Prescott, Ontario. From the late 1800s onwards, it was principally used by pleasure craft though commercial goods continued to be on- and off-loaded at the Canal Basin (now filled in) close to the city centre into the 20th century. In 1925, the Rideau Canal was designated as a National Historic Site. In 2000, the Rideau Waterway was declared a Canadian Heritage River in light of its historic significance and superb recreational facilities. In 2004, a Celtic Cross was erected beside the locks at Entrance Bay to commemorate the sacrifices and achievement of the mostly Irish workers who built the Rideau Canal. Three years later, UNESCO named the Rideau Canal a World Heritage Site. It is the only North American canal dating from the golden years of canal building in the nineteenth century which is operational through its entire length with most of its original buildings intact.


Corbett, Ron. 2007. The Rideau Canal, Then and Now, Magic Light Publishing, Ottawa.

Conroy, Peter. 2002. Our Canal, The Rideau Canal in Ottawa, General Store Publishing House, Burnstown, Ontario.

McKenna, M. J. (ed.), 2008. Labourers on the Rideau Canal, 1826-1832: From Work Site to World Heritage Site, Borealis Press, Ottawa.

Passfield, Robert W., 1982. Building the Rideau Canal: A Pictorial History, Fitzhenry and Whitside in association with Parks Canada, Don Mills, Ontario.

———————–, 2013. Military Paternalism, Labour and the Rideau Canal Project, AuthorHouse LLC, Bloomington, IN.

Tulloch Judith, 1981. The Rideau Canal: Defence, History and Archaeology, No. 50, Transport and Recreation, Parks Canada, Environment Canada.

Watson, Ken, 2013. Bye By, Rideau Canal World Heritage Site,

———————-, 2014, History of the Rideau Canal,

Images: Lieutenant-Colonel John By, Royal Engineers Museum

Rideau Canal Locks at Bytown, Etching, Library and Archives Canada, PA-133872