Video

A fire at the Fairways Apartments in Boulder on Saturday night left two people critically injured and many families out of their homes. Watch »

Firefighters have halted their investigation inside a Boulder apartment building that was badly burned Saturday because crews have determined the structure is not safe.

The charred three-story building at the Fairways Apartments complex, 5620 Arapahoe Ave., has been turned over to property management and insurance companies, and Boulder police spokeswoman Sarah Huntley said engineers are going to “shore up” the structure before investigators go back in. That could take a few weeks.

Once the building is safe, Huntley said, fire investigators will try to determine a cause and origin; builders will determine whether the structure can be saved; and officials will work to meet the needs of residents eager to collect what’s left of their belongings.

Fire investigators on Sunday “felt very uncomfortable with what they were walking through,” Huntley said. The third floor on the east side of the building is completely collapsed, weighing down the floors and putting pressure on the water-logged material that is holding up the building.

“It could give way at any time,” Huntley said.

Due to the stalled investigation, she said, fire crews can’t speculate about where or how the fire started.

Benny Chavez, a maintenance technician for building owner Thistle Community Housing, said his crew’s preliminary investigation indicates the fire started in a unit on the second floor on the east side. He said it appears to have started in the kitchen.

Crews were called to the apartments about 7 p.m. Saturday and found flames shooting from the roof. The burning building contained 10 units housing 32 residents who have been displaced. Three other buildings in the complex weren’t burned but were evacuated.

Fire crews were battling the two-alarm fire hours after it began, and Regional Transportation District buses were brought to the scene to keep evacuees warm.

Most of the more than 200 residents who were evacuated that night said they learned of the blaze either by seeing it, smelling it or hearing about it from someone who was pounding on their door. Susan Andre, resource development director for Thistle Community Housing, said the building has smoke detectors and alarms, but they stopped working after the fire caused the electricity to blow out.

Boulder Fire Chief Larry Donner said the building did not have sprinklers because it was built before city code required them.

Although the Saturday blaze was “one of our more serious fires,” Donner said it could have been worse. Just a few years ago, all the buildings were renovated to replace wood-shake shingles and siding with non-combustible materials.

“With the other exterior finish, we would have most likely lost more buildings,” Donner said. “We would have had a real difficult time controlling the fire.”

The Fairways blaze is one of several apartment fires in Boulder since 2006, including an apartment complex fire on University Hill in July that displaced about 50 people; an apartment fire at 1821 22nd St. in May that left dozens of people without a home; and two fires at the Gold Run condominium complex in January 2006 and in October 2007.

No one was seriously injured in those fires.