LAKEWOOD, Colo. (AP) — Four people died after a semi-truck hauling lumber lost control and plowed into vehicles on a crowded section of Interstate 70 near Denver, triggering explosions and a fire so intense that it melted the roadway and metal off of cars, authorities said Friday.

“It was crash, crash, crash and explosion, explosion, explosion,” said John Romero, a spokesman for the Lakewood, Colorado, police department, describing the 28-vehicle chain reaction of blasts from ruptured gas tanks.

The truck driver, Rogel Lazaro Aguilera-Mederos, 23, of Houston, was arrested on suspicion of vehicular homicide as police continue to investigate what happened.

Six people were taken to hospitals with injuries but their conditions were unclear Friday.

“There is just a bunch of debris from this crash that took place. The carnage was significant, just unbelievable,” another department spokesman, Ty Countryman, said.

Officials say Aguilera-Mederos, who sustained minor injuries, was headed down a hill when he lost control and slammed into traffic slowed because of a previous crash ahead of him on I-70 involving a school bus and a tractor-trailer.

There is no indication the crash was intentional and that drugs or alcohol were a factor but investigators were looking at whether his truck’s brakes were working, Countryman said.

I-70 is Colorado’s vital east-west highway that connects the mountains with the plains and traffic has grown worse as the state’s population has boomed. The crash happened just after the highway descends from the Rockies, where signs warn drivers to check to make sure their brakes are cool and working after traveling down the steep grades.

There are also ramps on hills off the sides of the highway for trucks that lose their brakes so drivers can exit and slow down before hitting other vehicles.

Workers cleared the burned and mangled wreckage from the highway and worked quickly to replace the top layer of burned pavement on Friday. A burned tractor-trailer hauled away was barely recognizable except for its size and its smokestack.

Aguilera-Mederos is scheduled to make his first court appearance on Saturday to be advised of his rights. A judge also may consider bond during that initial advisement hearing. There was no information on whether he is represented by an attorney.

Formal charges have not been filed by prosecutors, Pam Russell, a spokeswoman for the Jefferson County district attorney’s office, said.

Federal agencies are also monitoring the investigation. The National Transportation Safety Board said its teams get involved when the agency sees an opportunity to issue new traffic safety recommendations. The Federal Motor Carrier Safety Administration, which regulates and provides safety oversight for large trucks and buses, said it is working with state and local authorities to assist in any way it can.

Copyright 2023 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

Join our Newsletter for the latest news right to your inbox