A man was fatally shot on a BART train at the West Oakland Station Saturday night.

S.F. Gate reports the shooting occurred at 7:49 on the train bound for San Francisco. Witnesses told ABC 7 that just before the doors opened at West Oakland Station, a "disheveled looking man," who had got on the train at either the Rockridge or MacArthur stations, pulled out a gun and shot a passenger who was sitting next to the train door. The suspect then fled on foot outside the station.

One witness said he administered CPR to the victim, and noticed he was holding a knife.

25-year-old Brad Chapin, who was on the train at the time, told the Contra Costa Times, "Everyone just got down on the ground. People were screaming. It was chaos. We didn't know if there were terrorists there or what." BART spokesman Jim Allison confirmed this morning that the shooting was an isolated incident, and not related to a terrorist plot.

Here's a video shot on the train, following the sound of shots fired. It's quite scary:

KRON reports that a man was detained by police Saturday night, but that it was not the shooting suspect, who remains at large. BART officials described the suspect as a bald, slim, 6-foot-3 Black man, wearing a green hooded jacket with tan military-style boots and a backpack.

According to Allison, the West Oakland Station, which was closed overnight, has reopened as of 8 a.m. this morning.