One man was burned and an explosive cloud of propane moving across Mill Woods was bad enough. Then fire crews realized it was seeping into the sewers.It sounds like the plot line for an apocalyptic movie but it happened right here; the 40th anniversary is Saturday.The 228,000 gallons of propane created an unpredictable, moving bomb underneath the neighbourhood that blew off toilet lids and manholes as the pressure built, leading to one of the largest peacetime evacuations in Canada. As the day wore on, it started flowing through the deep storm sewer toward Terwillegar, chasing Kaskitayo residents from their homes at midnight.Fire crews struggled to determine who owned the leaking pipe, and how to flush the sewer, as they worried homes across the subdivision could ignite in flames. Eventually, the gas wafted out into the river valley near Riverbend and the provincial government called an inquiry.It’s a story worth remembering. Not just because of the remarkable progress that came out of this one incident, but because we still live with the danger. The city is criss-crossed with thousands of kilometres of high-pressure pipelines. This could happen again.For Peter Clark, the story is personal. He was delivering a load of glass windows for homes under construction in Mill Woods and decided to finish the job before breaking for lunch. He was driving slow and vaguely recalls a white cloud he thought was smoke.“The next thing I knew, I got this very strong smell of propane. The truck stalled and the world just went up around me in flames,” said Clark, who went back to the scene with me this week to look around. That day he jumped out of the vehicle and ran with his clothes on fire and rolled in the snow. He survived with third-degree burns to 30 per cent of his body. He was in the hospital for nine months.One of the high-pressure propane lines that still runs under Mill Woods had been nicked by a contractor roughly two weeks earlier. It had three deep gouges and slowly corroded. Propane seeped to the surface, creating a pond 20 metres by 35 metres. While it was cold, the gas hugged the ground and moved slowly. But that morning, the warm sun caused the propane vapour to rise, primed for disaster. The explosion sparked by Clark’s engine burned for 16 hours.Later, Clark found out he drove down that road just before a school bus full of kindergarten children was scheduled to come through.
Propane leaking from an underground, high pressure pipeline exploded in Mill Woods in 1979.
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Near the leak, at roughly 12 Avenue and 41 Street, the propane flowed into the sewer through several catch basins. Two kilometres away, drainage crews were working underground. Subforeman Nick Hendrey told a Journal reporter his team had just built a new manhole in the underground pipe they were constructing. Fifteen minutes after Clark’s accident, Hendrey’s team looked up to see their main exit blocked by a “river of fire.”They scrambled to safety through the newly opened manhole, lucky to be alive.Officials shut off gas to all furnaces in the neighbourhood and called 100 Edmonton Transit buses to pick up children from schools and day cares. Emergency crews went door to door, telling people to get out. Roughly 19,000 people evacuated, with families and children separated for hours in an era before cellphones and organized emergency response plans.Barry Lamb, who went on to become deputy fire chief in Edmonton, remembers the explosion as one of his first fire calls. He spent the night putting out smouldering fires of straw and coal, which were being used to thaw the ground for new home foundations. With all the propane in the air, officials worried those fires could lead to new explosions.
The Mill Woods propane explosion sparked one of the largest peacetime evacuations in Canada’s history.
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Later, this incident lead to Edmonton setting up a specialized hazmat, or hazardous materials, team which predicts how toxic gases and other dangerous material will react on any emergency call.The provincial inquiry lead to the formation of the Edmonton Area Pipeline & Utility Operators’ Committee, which co-ordinates safety in the capital region. It also led to the non-profit Alberta One Call, a voluntary registry that allows contractors, homeowners and anyone planning to dig deeper than 30 centimetres to call ahead and have the line located for free.Today, industry representatives are trying to make it mandatory to register underground infrastructure and call before you dig. Bill 211 passed second reading in the provincial legislature and was at committee this week. It likely won’t pass third reading before the election is called, but Alberta One Call’s Mike Sullivan hopes all-party support will move it forward to formal consultation anyway.Despite the registry, damage to underground infrastructure is still common. The Alberta Common Ground Alliance recorded 4,356 incidents in 2016, with 24 per cent of the damage happening because the person digging failed to call.Clark went on to dedicate his life to burn victims. He started the Alberta Burn Rehabilitation Society and lobbied for better standards for fire resistant clothing. So many of the victims he met in the burn unit had injuries that could have been prevented.Today, the clothing regularly supplied on job sites is much easier to wear and higher quality, he said. Those achievements and the amazing support of the Mill Woods community helped him rebuild his life.Many people suffer terrible tragedies and no good comes out of it, said Clark. Well, that’s not the case here. “So many good things came out of this one.”A commemoration ceremony is set for 2-4 p.m. at the Mill Woods Public Library on Saturday.email@example.com/estolteRelated