Massachusetts Bay Transportation Authority police say the approximately 21-year man was struck in Belmont at about 6:20 a.m. Monday by an inbound Fitchburg Line train.
Police say the man was trespassing on the right of way at the Brighton Street crossing. The victim's name was not released.
The death remains under investigation but foul play is not suspected.
The investigation has caused cancellations and delays of up to 30 minutes on the Fitchburg Line.
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