SIGAlert: 405 SB Chain Reaction Crash Halts OC Commute

COSTA MESA, CA — A crash between a semi truck and six additional vehicles stalled rush hour traffic on the State route 405 Freeway Thursday morning, authorities said.

The crash was reported at 8:54 a.m. on the southbound side of the freeway near the State route 73 connector in Costa Mesa and involved a semi truck and a Toyota Prius, according to the California Highway Patrol.

At 8:55 a.m., CHP officers reported that a total of six additional vehicles became involved in the crash after the initial crash left the semi truck flipped onto its side. The crash left injuries, though it was not immediately known how many were injured.

The crash prompted authorities to shut down several lanes of the freeway and issue a SigAlert "until further notice" during busy rush hour commuting traffic.

As of 9:31 a.m., traffic stretched back on the freeway for nine miles — past Costa Mesa, and into Fountain Valley.

By 10:30 a.m., CHP officials canceled the SigAlert and announced that the roadway had been cleared. Traffic remained dense and sprawling back toward Fountain Valley as of 10:37 a.m.

No further information was immediately reported.

This is a breaking story. Check back for updates.