The 65-year-old woman and 59-year-old man were hit in the area of Washington Avenue between Cochituate Street and Middlesex Avenue, the Middlesex District Attorney's Office said on Tuesday. Police were called to the scene just before 6 p.m.
The victims' names were not released.
Witnesses said they saw the woman near the eastbound tracks of the Framingham to Worcester line just before she was struck. One witness began to climb down the embankment to help, but they noticed the 59-year-old man was already trying to pull her to safety, authorities said.
The crash caused authorities to close the track for hours as they investigated and cleared the scene.
It's unclear why they were on the tracks or what led to them being there.
The Middlesex District Attorney’s Office, State Police detectives, Natick police, and MBTA transit police are investigating the incident.
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