UPDATED 12/23/10 11:27 a.m.

CHICAGO (CBS) — Fellow firefighters are paying tribute to two fallen colleagues at the scene of a tragic fire at a South Shore neighborhood building.

As CBS 2’s Mike Puccinelli reports, the fire will go down as one of the worst in the history of the Fire Department.

Several firefighters were caught in a hail of falling bricks and timbers at the scene of the fire at 1744 E. 75th St. Wednesday morning. Firefighters Corey Ankum, 34, and Edward Stringer, 47, lost their lives, and 17 others were injured.

Ankum and Stringer died of blunt force trauma, as they fought the fire at the vacant Banner Laundromat and Dry Cleaners.

The building was a popular spot for homeless people to take refuge, and firefighters had been inside trying to find out if any homeless people had been trapped. Instead, it was the firefighters themselves who became trapped.

On Thursday morning, a lone firefighter stood and paid his respects behind the burned out building. He was too distraught to talk about the loss of his friends and colleagues.

Out front, another firefighter stood before a memorial that has been set in honor of Ankum and Stringer.

“It’s just tragic. It’s a shame. It just breaks my heart,” said Matt Vandrunen, a veteran firefighter from Lowell, Ind.

Vandrunen did not know Ankum or Stringer, but feels a bond with them nonetheless.

“Even though we’re a far distance apart, it’s never easy to hear of a brother being lost in fires,” Vandrunen said.

LISTEN: Newsradio 780’s John Cody reports

Meanwhile, investigators were on the scene, seeking to pinpoint the cause of the fire. A front-end loader scooped debris from the fire-blackened building, and dumped it into a wide pile in front of arson investigators.

From the back of the building, it is clear where roof structure ripped away from the wall, burying the firefighters under thousands of pounds of debris.

The fire broke out around 7 a.m. Wednesday. The building had a treacherous bow-string truss roof in the back, but since the fire was in an office area well below the ceiling, firefighters decided to go inside for a precautionary search anyway, Fire Commissioner Robert Hoff said.

But soon, a frantic emergency call was issued over fire radios.

“Mayday! Mayday! Emergency!” a fire official said on the radio call. “We had a collapse in the rear of the building. Part of the building came down. We’ve got guys trapped.”

After the collapse, firefighters feverishly tried to save their fallen brothers, by forming bucket brigades to remove bricks, and lifting teams to remove timbers.

Much of that debris now sits behind the building in two massive piles of wood, bricks and metal.

All the firefighters were ultimately accounted for, but Stringer and Ankum did not survive. A total of 17 more firefighters were injured.

At Chicago firehouses, memorial bunting hangs in the fallen firefighters’ honor, and flags have been lowered to half-staff, as the city and the Fire Department prepare to say goodbye to two of their own.

This was not how Vandrunen planned to end his year, but he says it’s the least he can do.

He said there “absolutely, absolutely” will be a contingent from the Lowell Fire Department at the funeral.

The tragedy hit Mayor Richard M. Daley personally too. Ankum’s wife is the mayor’s personal secretary, and the mayor knew the family well. He was tearful as he commented on the tragedy.

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“His wife, Dameka, has been one of my closest assistants; a true friend; a confidant,” Mayor Daley said. “Our thoughts and prayers are always with the brave firefighters who remain hospitalized as a result of today’s fire.”

As of Thursday morning, a total of five firefighters remained hospitalized, and all are expected to survive.

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