State police said the 21-year-old Richard Guerrier and 54-year-old Esther Louis of Philadelphia were killed in the 1:24 p.m. Monday crash on Route 309 in Whitemarsh Township, Montgomery County.
Police said their sedan broke down in the center lane of the highway. State police originally said they were struck by a sport utility vehicle while trying to get the car out of traffic. But the county coroner's office said Tuesday that they were not struck while pushing the car but while Guerrier was looking under the hood as his mother stood off to the side.
The SUV driver was treated at Abington Hospital. The accident remains under investigation.