Investigators with the Denver Police Department face a daunting task in sorting out a 104-vehicle pileup on Interstate 25 near the Logan Street exit on Saturday morning.
Authorities say one person was killed on the snow-covered road and about 30 people were taken to the hospital.
Those people who needed medical attentition understandably leave their car behind, presenting one of the first challenges for investigators.
“It becomes somewhat of a task to match up people with vehicles," Arnold Wheat of Accident Reconstruction Services in Wheat Ridge says. Wheat is a former Arvada police officer.
Wheat is not part of the police investigation into Saturday's pileup but says standard procedure is to interview witnesses and take photographs and measurements. Where each vehicle came to a stop also would be noted.
"Knowing where a vehicle ended up and what vehicles were around it and then assessing the physical damage of each vehicle you can piece together who hit who and in what order," Wheat says.
But he adds that at times can be impossible to determine if a vehicle was going too fast for conditions or if a vehicle did slow down in time only to be pushed into another vehicle. That's a task made more difficult by bad weather.
"You have snow-covered and icy surfaces," Wheat says. "So the ability of the tires to leave marks on the pavement is pretty limited. So I would be surprised if there were any tire marks," he said, adding that any skid marks on snow could melt away.
If fault can't be assessed, according to Wheat, each driver's vehicle insurance ends up covering the damage.
The Denver Police Department is not commenting until the accident investigation is complete. A department spokeswoman says the report should be finished late this week or early next week.