CHICAGO (STMW) — Elevated train service on the CTA’s Brown and Purple lines was suspended for nearly six hours Tuesday morning between the North Side and the Loop as firefighters put out an extra-alarm fire at a 124-year-old shuttered school in Lincoln Park.

All fire companies were working on the fire at the former James Mulligan Public School Building, 1855-1863 N. Sheffield Ave., Fire Media Affairs said at 2:11 a.m. Crews were still chasing hot spots as of 9:30 a.m. and expected to stay at the scene most of the day, officials said.

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Brown Line service resumed between Fullerton and the Loop about noon, according to the CTA. It had been suspended for nearly six hours as crews cleared ice from the tracks caused by water used to fight the fire, CTA officials said.

Express Purple Line service had also been suspended but was expected to be in normal service for the evening rush, officials said.

The blaze appeared to be on the top two floors of the building, which has been under construction.

Firefighters battle a fire at a building in Lincoln Park. (Credit: Network Video Productions)

Firefighters battle a fire at a building in Lincoln Park. (Credit: Network Video Productions)

Kristina Satek said her boyfriend lives in a home directly south of the school, and she saw the flames from his third-story window.

“I was in the kitchen, and I saw, like, a burst of flame come from the window,” Satek said. “And I don’t know if that was like, maybe the window bursting out or something. We just grabbed our stuff and left.”

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She said work at the former school building has been going on for more than a year; crews have been re-sealing the windows and hand-cleaning the bricks.

“Whoever worked on it is probably pretty bummed out right now,” Satek said.

The northern side of Satek’s boyfriend’s home appeared to be covered in ice, as was most of the school building as fire crews continued to work the fire Tuesday morning.

A sign on the fence outside the school read, “Warning: Guard Dogs on Duty; Survivors Will Be Prosecuted.”

A fire department source confirmed firefighters were confronted by two Rottweilers, which were taken out of the building and handed over to animal handlers. Neither the dogs nor the firefighters were hurt, the source said.

The building, which first opened to students in September 1890, was being considered for historic landmark status in February, according to a city document. It was closed in the early 2000s and had remained vacant until the Board of Education sold it to a private developer.

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(Source: Sun-Times Media Wire © Chicago Sun-Times 2014. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed.)