A man claiming to have a gun appears to have commandeered a subway intercom system this weekend, sparking chaos on a Manhattan train.

The frightening incident occurred at around 9:30 p.m. on Saturday. According to Alexandria Neason, the southbound 1 train was pulling into Harlem 125th Street when a man's voice was suddenly audible over the MTA speakers. "He was loudly and very aggressively yelling 'I have a fucking gun,'" said Neason. "Everyone froze as they heard this. The doors hadn't opened yet."

When the doors did eventually open, Neason says that the entire train emptied out onto the platform, suggesting that the rest of the cars had heard the threat as well. Amid the confusion, a man on the platform began screaming, "He has a gun, get downstairs!"

Roughly 100 people on the elevated platform fled for the exits. Many kept running when they got to the street, joined by flower sellers and others who'd observed the commotion, according to Neason.

"In the moment I was thinking: Okay, well I guess it's our turn for a mass shooting," Neason, who works as a staff writer at the Columbia Journalism Review, told Gothamist/WNYC on Monday. "Later when I was at home safe, I was thinking how heavy it is that I could even think that."

A spokesperson for the NYPD hasn't responded to questions about the incident. A source in the MTA, who said he was not authorized to speak about an ongoing investigation, said that police arrived shortly after the train evacuated, but found "no indication of a gun.”

The transit authority concluded that someone had broken into the conductor cab, accessed the PA system, and made the phony announcement to create mayhem. “There was no major incident," the source said, "but it’s like shouting fire in a crowded theater.”

False reports of shootings have sowed mass panic and confusion on the subway in the past, most recently leading to a stampede at the 34th Street Herald Square station earlier this year.

Pranks involving subway intercoms have also occasionally been reported in the system. Those stunts seem to be particularly common on the R62 trains that the MTA purchased in the early 1980s, and which remain in use on the 1 and 3 lines. The MTA source speculated that the cab doors leading to the PA system may be particularly easy to break into.