Pandemonium broke out on a B train on the Upper West Side shortly after 8:30 this morning after someone caused a panic, straphangers said. An FDNY spokesperson confirmed that an "emotionally disturbed person" [EDP] caused a disturbance around 8:30 a.m. at the 81st Street-Museum of Natural History stop—officials first responded to a call about a stabbing, which was subsequently determined to be unfounded. But EMS did transport an unidentified EDP to Roosevelt Hospital for evaluation.

The incident sent commuters streaming out of the station in what one commuter described as "a mass evacuation w/people screaming and stampeding and the police are rushing to the scene." The FDNY spokesperson said no injuries were reported.

No arrests have been made, and the details of the incident remain murky. One NYPD source told the Daily News that a woman was screaming at commuters, and that "everyone was panicking because they didn’t know what was going on and started reporting things to 911 even though they didn’t witness anything."

The MTA confirmed there was an incident at the station, followed by delays on the B and C lines.

Meanwhile, in Brooklyn, commuters encountered long delays on the B line due to signal problems at the 7th Avenue B/Q station.

This morning's commute also saw service changes and delays on the 1, 2, 3, 4, 5, 6, J, Z, N, Q, and R lines. BINGO?