The crew detected an odor in the first car just before 6:45 a.m. and asked passengers to move into the other cars. When the crew did not see anything that warranted further action and continued on to 30th Street Station, said Jim Jordan, assistant general manager for public safety.
About a mile from the station, the engineer noticed smoke and then flames. The three crew members then helped evacuate about 500 passengers through the doors and emergency windows, Jordan said.
SEPTA also evacuated about 500 people that were on a train that was on an adjacent track.
There were no reports of serious injuries.
The rail car, which went into service in 1965, was completely destroyed within minutes. It is the first time a blaze has completely engulfed a SEPTA vehicle, said Joseph Casey, SEPTA general manager.
SEPTA spokeswoman Jerri Williams said the fire started either in a heater or a traction motor.
"I can tell you there is absolutely no indication it is strike related," said SEPTA spokeswoman Jerria Williams.
Alicia Boyd, 40, a data entry clerk, got on the first car of the train in Overbrook.
"It was smoking when we got on," she said. "It smelled like burning rubber."
Before the train pulled out of the station, passengers in the first car were moved to the back of the train before it burst into flames, SEPTA officials said.
The train then stopped and all the passengers on the train got off, Boyd said.
"The whole front car was black and melting," she said, adding that flames leaped out of the windows. "It was incredible."
Service on the R5 and R6 Cynwyd lines was suspended west of Suburban Station for two hours because of the blaze. The fire also disrupted Amtrak service between Philadelphia and Harrisburg until 8:30 a.m.
The city's Office of Emergency Management arranged for school buses to transport stranded passengers to Suburban Station.
