The layout of a Toronto propane depot hastened the 2008 explosion that leveled the site and resulted in the deaths of two people, a report by the Ontario Fire Marshal's report suggests.

Recommendations outlined in the report reveal that investigators believe the structures, trucks, fencing and vegetation surrounding the depot created "congestion" which increased the severity of the explosion.

Chris Williams, manager of fire investigations with the Ontario Fire Marshal's Office, says approval criteria for propane sites may need to be reconsidered.

"It's a complex consideration here, but the investigative team determined that the congestion -- the physical structures, equipment and vegetation -- contributed to turbulence within the vapour cloud," Williams said in an interview with ctvtoronto.ca

"The turbulence in the vapour cloud caused a unique reaction to increase the severity of the explosion.

"… If you take into consideration the earlier recommendation of the congestion, they may need to require changes in their site approval criteria."

The report concludes that a tank-to-tank transfer caused the Aug. 10, 2008 explosion at the Murray Road depot where several thousand cylinders of propane, bulk liquid propane storage tanks and cylinders of industrial gas were stored.

A mushroom cloud erupted over the site, near Keele Street and Wilson Avenue, killing Parminder Sighn Saini, a 25-year-old Sunrise employee, and damaging hundreds of neighbouring properties.

Firefighter Bob Leek died of a heart attack in the backyard of a nearby home that was damaged.

The report has been filed in court, and City Councillor Maria Augimeri obtained a copy earlier this week. She says the recommendations confirm what neighbours had long believed: that the depot was too close to a residential area.

"You have industry regulating itself, just like Walkerton, and it doesn't work. Industry will not self-regulate to the extent that citizens require and demand."

The full report from the Fire Marshal's Office is expected to be released to the public next week.