DES MOINES, Iowa (AP) — Authorities say 20 to 25 train cars derailed near Des Moines area after a small bridge collapsed. The Des Moines Register reports that the Polk County Sheriff’s Office says the collapse happened Friday morning in the northeast part of the county. It closed roads in the area for nearly 12 hours.

Sgt. Ryan Evans, of the Polk County Sheriff’s Office, described what happened as a “mess.” The sheriff’s office is assisting Union Pacific with the investigation.