Commuters biked, walked, juggled carpool schedules and hitched rides as a strike ground the city's transit system to a near halt for a second day Wednesday, a morning rush worsened when a regional rail train caught fire.

Regional rail lines are running because their workers are represented by a different union. But trouble hit around 7 a.m. when a car caught fire as it headed downtown, causing delays and confusion. A Southeastern Pennsylvania Transportation Authority official said it was likely an accidental electrical fire, but the cause has not been determined.

More than 5,000 members of SEPTA's largest union walked off the job early Tuesday, leaving thousands of people struggling for ways to get around.

"I can't take the whole strike off," said Niki LaGrone, 27, a Catholic school teacher in North Philadelphia, as she prepared to take regional rail as far as it goes and then walk a mile and a half to school. "I'm going to have to show up. ... Hopefully, I can find somebody when I get in to work to help me out."