PHILADELPHIA COUNTY, Pa. (WHTM) -- After five fires, a federal agency wants Pennsylvania's largest transit authority to stop using a railcar that makes up the majority of its fleet.

The Southeastern Pennsylvania Transportation Authority (SEPTA) operates 225 Silverliner IV railcars in its passenger fleet, more than half of all passenger-carrying cars in the fleet.

According to the National Transportation Safety Board (NTSB), electrical fires have damaged or destroyed Silverliner IV cars five times in the past year, prompting an investigation.

The investigation found that the design of the cars represent "an immediate and unacceptable safety risk because of the incidence and severity of electrical fires that can spread to occupied compartments."

The cars, which initially entered service

See Full Page