A rear-end collision by a pickup into a van carrying Casper Re-entry Center inmates in downtown sent probably more than 10 people to the Wyoming Medical Center on Tuesday afternoon.

"Without having complete information we're certainly investigating at this time what might have been a medical condition that led to this crash," Casper Police Chief Keith McPheeters said in front of the Casper Fire-EMS station.

Police and fire vehicles had blocked much of the intersection at First and David streets, and some traffic was diverted north on Market Street.

The pickup and van were traveling westbound on West First Street, when the collision happened immediately east of the intersection with David Street.

Shards of glass and vehicle parts were strewn on the street and the sidewalk at the point of impact.

The force of the collision pushed the pickup and the van across David Street and onto the sidewalk in front of the fire station.

McPheeters said the van was taking about CRC residents back to the facility at 10007 Landmark Lane.

Despite being in front of the fire station, first responders had to scramble to find ways to take the passengers and the driver of the pickup to the hospital.

"It was very chaotic here, a lot of people were in duress," McPheeters said.

The investigation is new, witnesses were available, and the driver of the truck is receiving treatment at the hospital, so it will be a while before police know whether the pickup driver will be cited, he said. "We will continue with our investigation, and if and when citations are appropriate we will deal with that."