Anyone trying to run to SFO Tuesday afternoon for the Thanksgiving holiday could encounter a snag unless they avoid the 101 freeway until they're further south.There was a multi-vehicle injury crash on southbound 101 in San Francisco Tuesday afternoon, just north of the Cesar Chavez offramp. As KPIX reports, the crash occurred around 1:30 pm and involved one overturned vehicle. It's not clear how many people may have been injured in the crash. The CHP said that individuals involved sustained "mild to moderate" injuries.The crash and its aftermath initially blocked three lanes of southbound traffic, backing up cars well into San Francisco. Since then, one lane opened up, but two lanes were reportedly still closed as of 2 pm, per KRON4. Motorists heading down the Peninsula, to the aiport or elsewhere, were being instructed to use I-280, or to try to get on 101 south of Cesar Chavez.This is a developing story.