It happened at about 1:15 p.m., SEPTA said. A person on the tracks near 30th Street was struck by a Market-Frankford Line train, and was later pronounced dead at the scene, they added.
SEPTA officials said Wednesday afternoon that the matter "appears to be a suicide."
Due to the accident, trolleys are not operating in the tunnel and are being diverted to 40th Street, transit authorities said. Shuttle buses are in operation taking passengers from 15th Street to 40th Street station, they added.
"Passengers should anticipate delays and crowded conditions," they noted on social media.
Anyone having thoughts of suicide, or worried about another person believed to be considering suicide should call or text 988 or contact the PA Suicide Prevention Taskforce.
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