Firefighters were still on the scene of a smoldering warehouse in Bridgeport this morning, pouring water on hot spots after a 5-11 alarm fire raced through the five-story building as a third of the department's on-duty personnel fought it.



The blaze was spotted by a fire chief passing by the former Harris Marcus Group building at 3757 S. Ashland Ave. shortly after 9 p.m. Extra alarms were quickly called as the fire spread throughout the warehouse and the roof collapsed and the more than 200 firefighters contended with frozen hydrants and icy ladders. The fire was finally brought under control around 12:30 a.m.



Chicago Fire Cmsr. Jose Santiago said the fire was Chicago's largest in seven years. "This was a very large fire, unbelievable fire load, a lot of wood, timber, old stuff, varnish," Santiago said on the scene. "Once it caught, it caught and ran.



"Everything is wood inside these buildings, beautiful façades on the outside. They've been up for a long time. When they start burning like this, they start coming down," Santiago said.



The commissioner said the freezing cold made the firefighters' job tougher. "We run into a lot of problems, like the ice weight on the building and ladders," Santiago said. "We had the Water Department to come out and steam off our ladders."



Heat from the fire could be felt several blocks away as flames climbed into the sky and ash rained down on cars.



"You could see the embers from the highway," said Darcy Benedict, a 28-year-old UIC medical school student. "I could see blue flames rising up."



Benedict and her boyfriend saw the fire from Interstate 55, a mile away, and got off the highway to get a better look.



At least 40 people stood behind police tape, bundled up and taking videos with cellphones. Several wondered how firefighters would be able to contain the blaze.



The commander at the scene called for a 5-11 with two "special alarms" to bring in special equipment and more manpower as the massive five started spreading to other buildings.



"I'm looking at the south side of the main fire building and there's a big portion of exterior wall and roof collapse," Fire Department spokeswoman Meg Ahlheim said as firefighters made progress around 10:30 p.m.



Special alarms are rare. A 5-11 with two special alarms was called in 2006 when a fire gutted the historic Wirt Dexter Building in the South Loop. That fire broke out before 3 p.m. on a weekday, snarled downtown traffic and forced the CTA to stop service on Loop L tracks.



There was a 5-11 alarm fire in the Avondale neighborhood on the Northwest Side last year. That fire burned for hours and required about 200 firefighters, but no special alarms were called.



Alarms normally escalate one at a time beyond a normal fire response up to a fifth alarm, though the scene commander skipped a fourth alarm Tuesday night once the fire jumped to another building.