A multi-vehicle crash closed the entire Golden Gate Bridge for about 45 minutes Tuesday morning at the end of the morning commute.
Crews cleaned up the debris from the crash in about 40minutes and reopened both lanes at 9:40 a.m.
But by then the traffic was already backed up for miles into both Marin and the City.
The traffic is supposed to remain bad through 11 a.m. and drivers were encouraged to use the Bay Bridge as an alternate.
CHP officers are investigating the crash, and it is still unclear whether any vehicles traveling in the opposite direction were involved, CHP Officer Nicole Pacheco said.
"Right now we're still trying to put all of the pieces together since it happened so recently," CHP spokesman Sgt. Trent Cross said.
Up to six vehicles, including a big-rig, were involved in the crash. Most of the vehicles were still drivable afterward but a tow truck was called to remove a tan Kia Rio from the scene, Pacheco said.
Two people suffered minor injuries, she said.