LAKEWOOD, Colo. (CBS4) -- Law enforcement officials say videos recorded before and during Thursday's deadly crash on Interstate 70 will be an important part of the investigation. Four people are confirmed dead after a semi truck plowed into several cars stopped on eastbound I-70 in Lakewood, sparking a massive fire.
A mechanical inspection will be done on the semi but the amount of heat from the damage may make that inspection incomplete, police said. Investigators will also be talking to witnesses and reviewing videos captured by other drivers.
"There's evidence of witnesses and video and things like that as opposed to mechanical evidence," Agent Ty Countryman with Lakewood Police said.
One video investigators are looking at shows a white semi heading downhill, about 5 miles from where the crash occurred. The semi swerves from the far right lane to the far left lane, and you see a white truck swerve onto the shoulder -- just as the semi driver passes a runaway truck ramp on the right side of the road.
The semi moves back into the center lane as it passes under a highway sign that warns, "TRUCKERS YOU ARE NOT DOWN YET -- ANOTHER 1 1/4 MILES OF STEEP GRADES AND SHARP CURVES TO GO"
"He picked up speed and just pretty much started swerving again. There [were] cars in front of him and as soon as he would get closer to the cars in front of him he'd swerve and so he doesn't hit them," the man who recorded the video told CBS4.
Investigators are working to determine whether it is the same truck that caused the fiery pile-up.
Another person driving in the area captured on video a white semi speeding past slower traffic just before the crash.
It was not long after that the crash occurred at Denver West Boulevard.
Lakewood police identified the driver of the semi that caused the crash as 23-year-old Rogel Lazaro Aguilera-Mederos. He now faces multiple charges of vehicular homicide related to the accident.
Investigators with the Lakewood Police Department said no alcohol or drugs were involved, but had no control over his truck.
"Where he lost control, that is still part of the investigation... We have witnesses that we want to to talk to again," Countryman told CBS4.
"We feel at this time we have enough probable cause to charge vehicular homicide," Countryman said.
"We don't have any indication that was an intentional act by the driver at all," he added.
The Jefferson County Sheriff's Office shared video taken immediately after the crash. It shows a huge plume of black smoke spreading up into the sky.
Investigators were still working to remove the wreckage of burned cars and semis on Friday morning.
The highway is not expected to reopen until Saturday.
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