The victim was driving Route 23 when they were shot at the intersection of Germantown and Abbotsford avenues around 10:30 a.m., a SEPTA spokesperson said.
They were taken to Einstein Medical Center where they succumbed to their wounds.
SEPTA did not identify the driver but said they were a 12-year employee.
"An investigation into this incident by SEPTA Transit Police and Philadelphia Police departments is ongoing, however, SEPTA Police have confirmed that a suspect is in custody," the spokesperson said.
Daily Voice has reached out to Philadelphia police for comment.
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