CHICAGO (CBS) — An extra-alarm fire ravaged an Uptown neighborhood condominium building Monday afternoon, and a firefighter was injured while fighting the blaze.

As CBS 2’s Jermont Terry reported, the fire broke out at the four-story, 13-unit Oxford Glen condo building at 817 W. Gunnison St., according to the Fire Department. Assistant Deputy Fire Commissioner Barry Garr said the fire started on the third floor.

The fire was raised to a 2-11 response, which automatically sends four engines, two trucks, one tower ladder, and other personnel to the scene.

The fire spread quickly to the roof, and the CFD feared the roof would cave in and trap firefighters. So they ordered all the firefighters out of the building with the sound of a fire truck air horn as an alarm.

The roof did give way, and pieces fell on top of a firefighter.

“As he was coming down the stairs, a large chunk of debris from the ceiling came down and hit him – we believe on the backside,” Garr said. “He walked on his own ability out.”

As of 5 p.m., fire crews were still working to get the blaze under control as thick smoke went on pouring from the building. It appeared that the fire started on the first floor and then moved swiftly to the top floor.

When the fire first started, residents reported hearing a fire alarm, stepping out into the hallways, and realizing they needed to grab anything they could quickly.

“I heard the fireman saying: ‘Get out! Get out!’ And I could smell a little bit of smoke – not a lot, but a little bit. And so I ran, I grabbed my wallet, my car keys, clean underwear, and out the door I went,” said second floor resident David Thomas.

“I got a phone call. So I went back to answer the phone, and when I got back, I saw, you know, I started hearing the smoke alarms, and I was so glad I got that phone call, because I was able to grab my dog and get out of the building,” said Phil Stucky, who also escaped.

Stucky watched in disbelief as the fire took over the entire structure.

“You hate to see the place you lived in for 20-30 years go up and smoke,” he said.

As of 5 p.m., fire crews were still focusing on the top floor of the building. The roof appeared to have collapsed.

Fire officials said everyone got out of the building safely, and no one other than the firefighter was injured.

“There’s no injuries except our pride,” Thomas said.

But all 13 condo units were destroyed.

It was not clear how many units were damaged.

The American Red Cross of Greater Chicago was at the scene Monday evening, along with warning buses for displaced residents, Garr said.

The 2-11 alarm was struck at 6:32 p.m., the Fire Department said. Firefighters continued to battle hot spots afterward.

All 13 units in the building were deemed uninhabitable after the fire, and all residents were to be relocated.

Firefighters believe contractors who had been doing plumbing work might be to blame for starting the fire. The cause will be deemed accidental, the Fire Department said.