LOS ANGELES – A crash involving two big rigs on the 5 Freeway in Mission Hills has closed multiple lanes, causing major traffic delays, according to the California Highway Patrol.

Four lanes of the southbound freeway are closed at Brand Boulevard. The carpool lane remains open.

The CHP says the lanes will remain closed for at least four hours as the cleanup and investigation continues.

The cause of the accident remains under investigation.

Motorists are advised to take alternative routes.