A four-vehicle crash on the 405 Freeway in Seal Beach injured 18 people today and triggered lane closures.

The crash at Seal Beach Boulevard happened just after 9 a.m., according to California Highway Patrol Officer Monica Posada.

All northbound lanes except the diamond and fast lanes were initially closed, but by noon all of them were reopened.

Of the 18 victims taken to area hospitals, two were considered “trauma” patients, said Orange County Fire Authority Capt. Tony Bommarito.