Philadelphia and SEPTA police are working together to investigate the fatal fight that took place in the station's concourse.
"According to video surveillance, a group of men, all who are believed to have known each other, were engaged in some type of physical confrontation," SEPTA's Carla Showell-Lee said.
She says when the air cleared, a 37-year-old man was found on the ground and pronounced dead at the scene.
"All of the people who were involved in that incident are with the Philadelphia police, and everyone is being questioned," she said.
The man's exact cause of death is not yet known.
Separately, two people were hit and killed on two different SEPTA train lines Tuesday night.
Showel-Lee says the first incident happened around 7:30, on the Media Elwyn line going towards Philadelphia.
That line was shut down temporarily. The 170 passengers on the train were put on shuttle buses.
Around the same time, something similar happened on the Norristown High Speed Line. A train going towards 69th Street struck a woman on the tracks near the Roberts Road station.
Both of the people struck are dead, and both accidents are under investigation.
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