The break happened around 10:30 a.m. on 38th Street at Woodland Walk.
A 20-inch line gave way, sending water flowing down the nearby roads and trapping a a car under an overpass.
"It was a little harrowing for a little bit," said driver Dennis Weinraub.
The water gushed for more nearly two hours from a break in a 16 inch main near the VA Medical Center.
Campus police directed traffic around the break and most cars got through. Weinraub, however, wasn't so lucky.
"My car didn't make it. When the water started getting a little higher I was wet up to my shirt. They told me I got out the window. I don't even remember what I did," he said.
When the main first ruptured water pressure at the VA Hospital, the University of Pennsylvania Medical Center and Children's Hospital dropped, but it was brief and pressure soon returned to normal.
"When you lose a lot of water, that's going to happen, there might be some low pressure," said Deputy Water Commissioner Debra McCarty.
For most of the afternoon 38th Street was closed between Walnut and University Avenue for repairs, which continued Friday evening.
No injuries were reported as a result of this water main break.