The Market-Frankford Line and trolley service in Center City were halted Wednesday afternoon in response to a possible transformer fire, officials said.
The Center City District issued an alert shortly before 3:15 p.m. that firefighters were responding to an underground transformer fire near City Hall.
A fire in that area was declared under control at 3:17 p.m., the Philadelphia Fire Department said.
SEPTA spokesperson Andrew Busch said the fire was was believed to be the result of a transformer, but there were no initial reports of a fire in the Market-Frankford tunnel.
There was smoke reported in an elevator shaft at Dilworth Park, but no reported injuries, Busch said.
SEPTA suspended service in the trolley tunnel and on the Market-Frankford Line from 30th Street to the Spring Garden station, Busch said.
Service in the trolley tunnel was later resumed. Shuttle buses were running between 30th and Spring Garden.