By Jim Melwert, Steve Beck, Nicole Brewer

READ MORE: Philadelphia Mayor Jim Kenney Undergoes Successful Surgery To Treat Irregular Heartbeat

PHILADELPHIA (CBS) — A four-alarm fire that gutted a vacant warehouse in Philadelphia Tuesday morning left a firefighter hospitalized and wreaked havoc on the morning commute for SEPTA El riders.

The blaze started around 2:30 a.m., engulfing a three-story building at Front Street and Girard Avenue in the city’s Northern Liberties section.

The fire, in a vacant warehouse located alongside the tracks of the Market-Frankford El, was placed under control at about 4:15 a.m., but caused headaches for commuters for hours.

The fire affected SEPTA service on the Market-Frankford El and the Route 15 trolley. SEPTA was forced to substitute El and trolley service with shuttle buses near its Girard Station. SEPTA ran shuttle service between the Huntingdon and Spring Garden Street elevated stations.

Inspectors were called to the scene to check the structural integrity of the El’s support columns. Service on the Market-Frankford El line resumed at about 2:30 p.m.

The firefighter was injured in a fall while fighting the blaze and was hospitalized in serious but stable condition with back injuries. He is expected to recover.

READ MORE: Philadelphia Phillies Legends Jimmy Rollins, Ryan Howard Could Earn Hall Of Fame Honors Tuesday Night

There were several road closures and detours in effect near the scene of the fire.

The fire-gutted structure next to the El. (Credit: Jim Melwert)

Demolition crews were called to the scene and conducted a controlled collapse of the building.

The exact cause of the fire remains under investigation.

Listen to KYW Newsradio for “Traffic and Transit on the Twos” to help you get around the scene.

READ: Travel Guide

MORE NEWS: Taylor Swift Fires Back at Rocker Damon Albarn After He Claimed She Doesn't Write Her Own Music