Violent altercation erupts on BART train, leaving passenger injured.

A passenger on a BART train in San Francisco was grazed by a bullet and pistol-whipped by another passenger during an altercation that began with an argument. The incident caused major delays and the suspect has not been found. The victim was later found at a different train station and hospitalized with non-life-threatening injuries. Police are hoping surveillance footage from the train's cameras will provide more information.