LAKEWOOD, Colo. (CBS4)– Investigators are still trying to figure out what caused a semi truck driver to lose control while driving on Interstate 70, before smashing into dozens of vehicles in Lakewood. Semi truck driver Rogel Lazaro Aguilera-Mederos, 23, faces four counts of vehicular homicide.
Four people were killed and 10 others injured in the crash on I-70 at the Colorado Mills Parkway on Thursday afternoon.READ MORE: FAA Investigates Mid-Air Collision Between 2 Small Planes Above Cherry Creek Reservoir South Of Denver
The Lakewood police department says no alcohol or drugs were involved, but Aguilera-Mederos had no control over his truck.
“Where he lost control still part of investigation. We have witnesses we want to interview to get time frame where this all took place,” said Lakewood police spokesman Ty Countryman.
One of those witnesses recorded a video on Lookout Mountain. He told CBS4 he took the video after being cut off by the semi driver.
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”
Identifying himself only by his first name Pedro he told CBS4, “He picked up speed and pretty much started swerving again. There were cars in front of him.”
He said the driver went up hill and passed runaway truck ramps. Police say they are trying to determine if it was the same truck, but Pedro said he is sure.
“It was the same truck because he had that white semi flatbed, with cargo, with cargo, wood cargo 2x4s.”READ MORE: 'Level Clear' Loosens COVID Restrictions, Business Owners Excited
It was not long after that the crash occurred at Denver West Boulevard. CBS News spoke with one victim who was still in the hospital on Friday, Leslie Maddox.
“I was stopped. Which meant someone would have to rear end me. But the whole front of my car was blown away, the glass was everywhere, all the airbags… and I was just there. Just… I did not know what happened at all,” Maddox said.
The investigation has determined the driver had a commercial driver’s license from Texas.
“He is cooperative like I said he spoke with us as far as attitude and demeanor I’m not going to comment,” said Countryman.
CNN reported that the brother of the truck driver said he was told by his brother after the crash that his brakes had failed.
Legal analyst Raj Chohan told CBS4, “It may provide some defense, or perhaps even a complete defense if the brakes were maintained properly but failed through no fault of the driver. On the other hand, if the brakes were not maintained properly, the driver or the company may be held to blame.”
Westbound lanes of I-70 reopened at 2 p.m. Friday. Eastbound lanes remained closed but were expected to reopen on Saturday.MORE NEWS: 'Read My Lips': Colorado Travel Expert Reassures Drivers Won't See A Gas Shortage
The victims killed in the crash have not been identified.