WILLARD, Box Elder County — A collision involving five cars on northbound I-15 sent 10 people to the hospital Thursday afternoon.

The accident happened near milepost 353 near Willard just before 2 p.m., Utah Highway Patrol trooper Cameron Roden said.

It occurred when a Mitsubishi collided with a bicycle, which was lost from an unknown vehicle and left on the freeway, causing the Mitsubishi to lose control and stop in the roadway. Roden said the bicycle had been reported to UHP just moments before the accident.

A Toyota stopped behind the Mitsubishi, but a Chevy Suburban ended up clipping the Toyota before heading into the median, winding up on its side after hitting the cable barrier, Roden said.

Then another Suburban traveling behind the group swerved to the right and hit the rear of the Toyota as well. A fifth vehicle also came into the crash area, sustaining minor damage, according to Roden.

There were 24 people riding in the five vehicles involved in the accident, and 10 of them were injured and transported to local hospitals. The worst injury was to a 2-year-old who was airlifted to an Ogden hospital in serious condition with head injuries, Roden said.

Southbound I-15 was closed for close to 15 minutes to allow the helicopter to transport the child. The left lane of northbound I-15 was closed, but traffic did move in the right and emergency lanes.

As of late Thursday evening, investigators still had not located the owner of the bicycle, Roden said. Anyone with information as to where the bicycle came from are asked to contact the Utah Highway Patrol.

—Ethan Thomas