VAN NUYS, Calif. (AP) — Authorities say 11 people were hurt, one seriously, in a multi-vehicle crash that blocked all southbound 405 Freeway in Van Nuys.

The collision around 9:30 a.m. backed up traffic for miles on the key Southern California artery.

The California Highway Patrol tells City News Service the crash involved a big rig, a catering truck and four other vehicles.

Los Angeles Fire Department officials say paramedics transported seven people for hospital treatment — one with serious injuries and six with minor-to-moderate injuries.  Four other people were treated at the scene and released.

The southbound lanes remained blocked for more than an hour and a half as crews worked to clear the scene.

The cause of the crash remains under investigation.