This Is What Caused The Massive 'Fire Ball' Explosion Under Toronto's Bathurst Bridge (VIDEO)

Toronto Fire Services (TFS) has completed its investigation following an explosion and massive fire underneath a bridge at Bathurst Street and Fort York Boulevard on Saturday evening.

Flames could be seen shooting out from under the bridge at 11:11 p.m., November 26 and now we know exactly what caused this to happen.

"We have confirmed that there was a boiling liquid expanding vapour explosion (BLEVE) during the fire," said Toronto Fire Chief Matthew Pegg in a series of tweets. "The BLEVE occurred when a number of propane cylinders were exposed to the heat of the fire. When cylinders fail, there is a large fireball produced and numerous projectile hazards."

That's exactly what was seen and felt by people nearby, in a neighbourhood surrounded by condo towers.

One video posted to twitter captured the moment the explosion occurred and drivers on the bridge could be seen turning around as fire and smoke inched its way onto the road.

Despite the bridge often times busy with both pedestrians and vehicles and the section underneath known to some as a homeless encampment, officials confirmed no one was injured in the incident.

"Fortunately, there are no reported injuries," said Chief Pegg. "@cityoftoronto staff are engaged in removing remaining hazards and making the area safe."

Some said the explosion made their entire building shake — once during the initial explosion and two times afterward when smaller fireballs could be seen erupting underneath the bridge.

"Are those propane tanks?" one person can be heard asking in a now-viral video on Tiktok that shows some people dangerously close to fire moments before the explosion. "Yeah, like, I would not go any closer," said another person in the video.

A portion of Bathurst Street was closed for several hours after the fiery explosion but reopened to vehicle and pedestrian traffic on Sunday morning.