TEMECULA – A trailer being pulled by a pickup truck overturned Tuesday on the Temecula Valley (15) Freeway, causing a traffic jam near the Interstate 215 connector.

A SigAlert was issued following the 12:49 p.m. crash on the southbound 15, just north of Winchester Road, according to the California Highway Patrol.

Traffic immediately began backing up on the interchange, as the wreck blocked the right lanes, the CHP reported.

The cause of the accident was under investigation.