A sport-utility vehicle whose driver lost control and crashed into a guardrail on snow-covered Interstate 95 near Carmel sparked the beginning of the worst motor vehicle pileup in Maine history, according to a narrative of the incident pieced together by Maine State Police investigators.

Investigators released a summary of their findings Wednesday, including a detailed description of the events that led to the multi-crash pileup on the morning of Feb. 25. Police do not anticipate any criminal charges or citations in connection with the crash. In the report, the investigators describe how drivers traveling behind the SUV swerved into the left-hand passing lane, crashed into other motorists and spun off the road as they tried to dodge the vehicle.

Within minutes, dozens of vehicles were involved in a chain of accidents that one Maine State Trooper described as “a giant pile of metal.”

More than 140 vehicles were left littered along a 4-mile stretch of I-95 before it was over.

Thirty-two people were treated for injuries, none life-threatening, and 17 people were taken to Eastern Maine Medical Center and St. Joseph Hospital, both in Bangor, for treatment.

Speeding drivers, operators driving too close to other vehicles, poor road conditions and reduced visibility were all factors in the pileup, according to investigators. It was snowing at the time and some snow had piled up on the road, but crews had started plowing two hours before the initial crash.

The downward slope of the road, a long-sweeping right-hand curve, and guardrails on both sides of the road that left drivers with nowhere to go were contributing factors as well, investigators found.

Injuries were likely limited by the fact that only one of the 149 people involved was not wearing a seat belt, said Lt. Sean Hashey, who commands State Police Troop B in Bangor.

“We think that seat belts absolutely led to the lack of fatalities and significant injuries,” Hashey said.

The timing of the crash, during rush hour and after local schools opened, may have also limited injuries, Hashey said. Most vehicles had only one or two occupants in the front seats, so there were few children involved.

According to the investigators’ findings, only six child restraints were reported in the crash and there were three occupants of a school bus carrying two high school-age students and an adult aide. One student had a scraped chin, but no one else in the bus was hurt, a school official said at the time.

“I think that if this had occurred on a school vacation week or a weekend, it would have been a different story,” Hashey said.

Trying to prosecute civil violations resulting from the crash would not be worth police or court resources, Hashey said. He hoped that people who were speeding would slow down under similar conditions.

“A lot of it comes down to driver behavior,” he said.

Data released by the Maine Department of Transportation last week showed that drivers averaged at least 10 mph faster than the recommended 45 mph limit on the highway at the time of the accident.

Maine State Police continue investigating the pileup, and an after-action review is planned for emergency agencies, Hashey said.