The incident happened near the Copiague station, near Great Neck Road and Railroad Avenue, shortly before 4 p.m.
A "trespasser" was on the tracks when they were struck by a train, an MTA spokesperson told Daily Voice. The victim was pronounced dead at the scene.
Additional details about the incident, including the victim's identity, were not immediately available.
Riders were experiencing scattered 15 to 20 minute delays on the Babylon Branch as a result, the MTA said.
This is a developing story. Check back to Daily Voice for updates.
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