CHEYENNE, Wyo. (AP) — Investigators are trying to figure out what caused train cars to derail west of Cheyenne.

Officials say 16 out of 166 cars along a Union Pacific line derailed Monday afternoon as they headed to North Platte, Nebraska, from Hinkle, Oregon.

Union Pacific Railroad workers responded along with Wyoming Highway Patrol, the Laramie County Sheriff’s Department, and Laramie County Fire District 1.

The derailed cars did not contain hazardous cargo.

No injuries were reported.

Union Pacific spokeswoman Calli Hite says the company is using different routes to get trains through the area.