One vehicle caught fire in the crash, on the southbound 405 Freeway approaching Magnolia Street.
Paramedics rushed three people to an area hospital. Their medical conditions were not immediately known.
One person refused to be transported to an area hospital, said Huntington Beach Battalion Chief Jeff Lopez.
A representative from the Coroner's Office was requested to the scene at 5:39 a.m., according to the CHP.
All lanes of traffic were opened at 9:21 a.m.
Copyright 2015 FOX 11 Los Angeles | Download our mobile app for breaking news alerts | Follow us on Facebook , Twitter and YouTube.