New video footage has surfaced showing a fiery explosion that took place after a transport truck loaded with a "highly flammable" liquid lost control and crashed through a median along Highway 401 late Tuesday night.

CP24 has obtained two videos that show the immediate aftermath of the collision near Brock Road in Pickering.

The first was taken from a dashboard camera of a vehicle travelling along the highway and shows a giant fireball exploding into the air following the initial impact.

The second video was captured by a man who lives in a nearby condominium. In it, a large fire can be seen raging in the distance. There are also several audible explosions heard.

“The first thing we heard was a crash and then another crash and then a ding. After that ding all we saw was white light,” the witness, whose name is Zach, told CTV News Toronto on Wednesday afternoon. “All we saw was the explosions and it just kept going off. It exploded about 25 times from 10:45 p.m. all the way to about 12:45 a.m.”

OPP Sgt. Kerry Schmidt said that it is believed that the tanker truck was travelling in the eastbound lanes of the highway when, for some unknown reason, the driver lost control.

Police said the driver struck the centre concrete wall and rolled into the westbound lanes, rupturing the truck's tank and result in the spill of 54,000 litres of flammable liquid. 

Schmidt said the truck "exploded into a fireball" as a result and the flames spread to an oncoming transport truck and passenger vehicle.

The fuel, meanwhile, leaked into drainage pipes along the highway and caused several smaller explosions which actually dislodged mahnhole covers

"The amount of energy that would have been required to blow these caps off, it is shocking to me,” Schmidt said.

'Tragic and horrific scene'

transport, fire, Pickering, 401

Schmidt said a collision reconstruction unit is on scene to piece together exactly what transpired on Tuesday night.   

"The situation is still very much evolving and ongoing," he said. "(There is) a lot of investigative work left to be taken care of. (It was) an absolutely tragic and horrific scene as first-responders tended to that incident last night," he said. 

"This will be an all-day affair for sure. There is a lot of work to be done. The bridge on Brock Road needs to be inspected. It took an incredible amount of heat. The light standards in that area, one of them in particular, will come down and be replaced." 

The road surface also sustained significant damage, Schmidt said. 

Pickering, crash,

"The explosions that were being reported in that area while this fire was ongoing actually extended not only to where the vehicle, the transport truck, was burning but as the fuel was pouring into the catch basins, there were explosions in the storm sewers that actually blew the storm sewers and the catch basins to pieces," he added. 

At one point, police advised residents in the surrounding area to keep their windows and doors closed as a precaution due to smoke from the fires. That directive is no longer in place.

“At this point it is not a dangerous good,” Schmidt said. “It is not toxic to my understanding.”

Closures could continue into Friday: MTO

The Ontario Ministry of Transportation told CP24 that lane closures could continue into Friday. Drivers in the eastbound lanes of the highway can exit at Brock Road and get back on by taking the on-ramp and the off-ramp. For drivers in the westbound lanes, they will be forced off at Highway 412 but can get back on at Liverpool Road. 

"There will be a lot of remediation work that needs to get done before we can reopen the highway," Schmidt said Wednesday. 

Images from the scene on Wednesday morning showed cars attempting to exit the highway using an on-ramp.

cars, pickering, crash

"This is a huge headache, I’m sure a lot of frustration for a lot of motorists... We don’t want people going the wrong way into oncoming traffic. It causes confusion, it can cause collisions and injuries," Schmidt said. 

"Wait your turn. We will help traffic continue to move."