Around 3:30 p.m. this afternoon, a BMW apparently caught fire on the westbound top deck of the Bay Bridge, causing a plume of smoke (seen here) backing up traffic past Yerba Buena island.

According to the KCBS traffic team, the vehicle has since been cleared and traffic is going again, but things are moving slowly all the way down to Cesar Chavez:

No word yet on what caused the 3-Series Beamer to go up in smoke, but it didn't appear to cause any damage to the bridge.