GLENWOOD SPRINGS — A trucker from Fountain, Colo. and a Washington state woman were killed Tuesday on Interstate 70 after a semitrailer tipped over in Glenwood Canyon and spilled 38-foot-long steel pipes into traffic. Two other people were injured.

The victims were identified Thursday by the Colorado State Patrol as Stanley Nichols, 44, of Fountain, and Samantha Middlebrooks, 21 of Vancouver, Wash. They were both pronounced dead at the scene by the Garfield County coroner.

“It was probably about the most horrific scene you could imagine,” said Randy Behr, of Avon, whose Subaru collided with one of the pipes but who was uninjured. “It looked like one pipe went through the semi and one went through the Toyota truck. One hit me farther down the road.”

Colorado Department of Transportation spokeswoman Stacey Stegman said the accident occurred just west of the Hanging Lake Tunnels in Glenwood Canyon, where the westbound lanes are elevated above the eastbound lanes. The Colorado State Patrol responded to the accident just before 8 p.m.

The accident closed all four lanes of I-70 through the night. The westbound lanes were the last to open just after 5:30 a.m. Wednesday.

A Freightliner tractor-trailer rig heading west tipped over onto its side while negotiating a right turn. Four of the large pipes it carried, measuring almost three feet in diameter, rolled down onto the eastbound lanes below and collided with an eastbound tractor-trailer, a silver 2004 Toyota Tacoma and the white 1997 Subaru Legacy that Behr drove, according to the patrol.

Nichols was driving the eastbound semitrailer and Middlebrooks was a passenger in the Tacoma.

The driver of the westbound, overturned tractor-trailer, Kenneth K. Muchiri, 55, of Houston, Texas, and Jonathon Middlebrooks, 29, of Vancouver, Wash., both sustained “moderate injuries” and were transported to Valley View Hospital. Jonathon’s wife was one of the individuals killed in the crash.

Behr said he was on the way home to Avon from an excavating job in Basalt. He came around a curve and saw what at first looked like a billboard crashing down onto the highway. He slammed on his brakes and quickly realized there were actually huge red pipes bouncing on the road. He’s guessing they weighed about 1,200 pounds each.

He watched one pipe coming toward him from the left and turned his car a little bit to try to lessen the impact. The pipe pinned his car to the guardrail, but he was uninjured, Behr said.

“It’s still running through my head,” he said. “It all just happened so fast and was so surreal.”

When he got out to see what had happened, he heard people yelling to see if anyone could get cell phone service. He helped others move one of the pipes so that somebody could drive to a spot where there was cell phone service and call 911, Behr said.

He said the scene was as horrific and odd as could be imagined, with the huge pipes coming down from above and the gruesome injuries.

“After getting as far as the Toyota, what I saw there was enough to stop any human,” he said. “The semi — it looked like it was filleted open.”

The Toyota was badly crushed by a pipe, Behr said.

It was unclear why the semitrailer tipped. Patrol Trooper Gilbert Mares said no citations were issued as of Wednesday afternoon. Alcohol and drugs are not suspected as factors. Asked if excessive speed was a factor, he said the accident was still under investigation.

“There’s a million what-ifs,” Behr said. “I don’t know if it’s really hit me yet.”

The Aspen Times contributed to this report.