By Paul Kurtz

PHILADELPHIA (CBS) — The Nutter administration is beginning to replace the city’s fleet of police cruisers as an investigation continues into a police car fire last week that led to a citywide service recall.

Administration spokesman Mark McDonald says the decision was made to recall nearly 300 Chevrolet Impalas after an investigation of the car fire on November 8th.

Officer Mark Kimsey had to be rescued by passersby after an accident during which his cruiser burst into flames.

When city fleet manager Chris Cocci inspected Kimsey’s vehicle, McDonald says, he found that a bolt was missing from the subframe.

“They torqued, or tightened up, all the bolts in question,” McDonald says. “They then promptly got all the vehicles back out on the road.”

McDonald says the fire marshal’s office is still trying to determine if the missing bolt had anything to do with the fire.

The recalled Impalas were purchased between 2007 and 2012.  McDonald says the older models are beginning to be replaced by 150 new vehicles. The phase-in should be completed by mid-February.

Cocci has asked General Motors to send a specialist to Philadelphia and try to figure out if the bolt was a factor in the fire.