Fire tore through a vacant warehouse on the border of Northern Liberties and Fishtown early Tuesday, destroying the building, injuring one firefighter, and leading SEPTA to suspend service along the Market-Frankford El during the morning commute.

The firefighter, who was not identified, was taken to Hahnemann University Hospital after hurting his back in a fall. He was released Tuesday afternoon, Executive Fire Chief Richard Davison said.

The four-alarm blaze broke out a few blocks from the Piazza at Schmidts in Northern Liberties, which has become one of the city's thriving areas for nightlife and apartment-dwellers. The building was owned by Liberty Homes Philadelphia, part of Piazza developer Bart Blatstein's Tower Investments.

The fire started around 2:30 a.m. in the 75-foot-by-75-foot warehouse on Front Street next to the El line between the Spring Garden and Girard stations. It escalated to four alarms within an hour as Fire Department commanders called in help from around the city, and firefighters battled the blaze by pouring water from ladder and snorkel trucks over the El tracks and the Girard station.

Neighbors heard sirens and an explosion as the warehouse went up in flames. Angie Morta, who lives about a block away, awoke to find her bedroom filling with black smoke pouring in from her open windows.

"I thought it was my house on fire, so I ran outside," she said.

The blaze was under control by 4:15 a.m., but concerns that the four-story warehouse would collapse onto the tracks led SEPTA to halt all trains in the area for more than 12 hours. SEPTA arranged for shuttle buses to transport passengers, but thousands were rerouted from their normal morning commute, and delays were unavoidable. Trains resumed running around 4:30 p.m.

The cause of the fire is under investigation.

A for-lease sign on the building listed Tower as the point of contact. Blatstein said Tuesday that the building was owned by an entity of Tower but declined to comment further.

The Department of Licenses and Inspections arranged for the emergency demolition of the structure, and by midday, piles of bricks and debris remained where the massive warehouse had stood.

Schmidts and Liberty Walk developments helped transform Northern Liberties, and his Avenue North brought new life to a section of North Philadelphia near Temple University. Blatstein also bought the building that housed The Inquirer for 87 years.

. No construction or zoning permits were associated with the building, and the site remains zoned for industrial use, according to city records.

. The building, like many of the neighborhood's vacant and underused former industrial sites, had a long history before the collapse of the manufacturing sector left it an empty eyesore. The property was home to the L.H. Parke coffee and dry goods company, kitchen and bath distributors Fruchter Industries, and Wood Superior, a woodworking company owned by Houser.