The State Patrol on Monday continued to look for the driver of a semitrailer truck who may have stopped in the traffic lanes on westbound Interstate 94 near Monticello last week to clear snow from his windshield moments before a fiery pileup that involved 29 vehicles.

Nobody was killed, but nine people were hurt in the chain-reaction crash that happened about 9:10 a.m. Thursday at the exit to County Roads 18 and 39, when a quick intense burst of snow made driving treacherous.

Investigators are still piecing together what led to the mishap, which closed the freeway for nearly 10 hours. But "it appears the [truck's] nonemergency stop may have played a role in starting the chain of events in the crash," the State Patrol said.

Ryan Peter, of Monticello, was right behind the truck, with a white cab and trailer, when it stopped in the right traffic lane. He said he assumed there had been a crash since the roads had turned to glaze ice. As he and a minivan slowed, they started to slide at a point where the road curved and sloped downhill.

"I was nervous, and scared," he said, noting that other traffic was coming up behind him. "My cousin was killed for the same thing. A semi rear-ended her."

Peter was able to maneuver into the left lane and pass the motionless semitrailer truck, and said he was aghast at what he saw. The driver had his cab door open and was leaning out to remove snow from the windshield.

"He probably could not see," Peter said. "It was crazy. He could have pulled off another 20 to 30 feet [to the right]."

Peter used his cellphone to grab some video as he continued on, seconds before the carnage began. He said he didn't know about the crash until he got home a few minutes later and heard the sirens. By then, the semitrailer truck had left the scene.

Heavy black smoke billowed into the air for hours after the crash that involved at least 15 semitrailer trucks and dozens of mangled vehicles, some pinned up against a concrete median. A truck carrying tractor tires burst into flames, and the fire spread to a number of nearby vehicles, patrol said.

A backhoe was brought in to help remove burned vehicles, tires and other debris.

Several drivers who were involved in the crash or may have seen it left the scene before first responders arrived, Shank said. The semitrailer truck had few identifying features and no name on the side. Shank said he's hoping someone saw something to help investigators find the truck and driver in question.

"If you witnessed the crash or have any information regarding the semi or its driver, please reach out to the patrol," Shank said.

Tim Harlow • 612-673-7768