The Long Rail Road is investigating a possible suicide attempt by a woman at the Bellmore station during Tuesday's evening rush hour, a spokesman said.
"She may have jumped in front of the train," he said by email.
Earlier, the railroad said a passenger was "not seriously injured" after a police monitoring service said a person had slipped and fallen between the train and platform.
The Babylon branch train the passenger was on was delayed 27 minutes, the spokesman said.
Two other trains also were delayed, one by about 20 minutes and one by about 10 minutes.
On July 2, Sima Hakimian, 65, of Great Neck, suffered minor injuries when she fell into the gap between the platform and a train car at the LIRR's Great Neck station, railroad officials said.
Hakimian, described by one witness as very petite, fell through the gap and ended up on her back next to the tracks as commuters were crowding on and off the train.
The LIRR said she suffered bruising after she lost her balance and fell between the platform and the train car around 5:45 p.m.
Hakimian's attorney said she was seriously injured when she fell 6 feet onto the LIRR tracks while exiting a train. He said the gaps between rail cars and the platforms at some stations remain dangerously wide.