Patten Towers resident Deborah Fuqua wipes her eyes after spending the night at the Brainerd Recreation Center after an electrical fire Tuesday night forced 241 residents to be evacuated.

As firefighters roared onto the street on Tuesday night, their trucks' ribcage-rattling horns and blazing lights trumpeting an imminent arrival, there was no way to tell whether they were heading toward an actual emergency, a maintenance problem or yet another in a long string of daily alarms at Chattanooga's Patten Towers.

While most alarms result in nothing more than some street-level excitement and a lot of noise, Tuesday's call for help forced a full evacuation as an electrical fire burned out of control in the basement of the early 1900s-era skyscraper. It was the second electrical emergency this year -- rescuers scrambled in January to contain problems stemming from Patten Towers' wiring.

This time, Chattanooga firefighters responded with their usual six companies at 10 p.m. Tuesday to face an actual fire sparked by underground electrical conduits. The basement filled with "black, acrid smoke and intense flames," and the temperature there shot up to 1,500 degrees, Chattanooga Fire Department spokesman Bruce Garner said in a news release. Firefighters shut off the building's power to stop the source of the fire from spreading to upper floors in the 11-story building.

The evacuation surprised residents, who are accustomed to frequent yet uneventful visits from Chattanooga's finest.

A 70-year-old woman who identified herself as Sally was among the residents waiting for answers at the Brainerd Recreational Center on Wednesday. Still dressed in her nightgown, she sat on a cot near a walker with a few bags hanging from the handles.

Firefighters had carried her wheelchair down 11 flights after going door-to-door telling residents to evacuate.

"They were real nice. One of them picked up the front of the chair and the other picked up the back and away we went," she said.

The 241 residents were taken to emergency shelters supported by the Salvation Army and American Red Cross. The number dwindled to 189 as residents' families began taking them in Wednesday, said Sandy Matheson, regional chief development officer for the Red Cross.

"We have a lot of people that are on oxygen, that need wheelchairs," Matheson said. "We're working with home health care providers to make sure they have a support system in place."

Residents' special needs often play a part in the large number of emergency calls from the aging building: 384 in 2012 more than 100 so far in 2013, according to fire department emergency logs. Fire and safety inspection records were not immediately available Wednesday.

Emergencies range from cooking fires to stalled elevators, and include a large number of problems that could be solved without summoning six companies of highly trained firefighters.

In 2012, emergency responders answered several calls to "assist invalid" residents, more than a dozen calls for "excessive heat" and near-constant calls for medical assistance.

In 2013 so far, firefighters have responded to more than 60 accidental alarms, almost 30 emergency medical calls and a single stalled elevator.

Patten Towers is one of Chattanooga's original skyscrapers, so fire officials always bring out the big guns, including an ambulance and a ladder truck.

Each response costs taxpayers an extra $530 for the expense of the captain, lieutenant and senior firefighters. The total cost was about $204,300 in 2012 and is more than $622,220 for 1,174 calls since 2010.

It's still unclear what sparked the Tuesday blaze that emptied Patten Towers.

"They're looking into it, and they might be able to make a determination," Garner said. "On the other hand, they may never be able to determine the exact cause of the fire. Just don't know right now."

The building's owners and property managers also are looking into the building's frequent calls for emergency service.

Joyce Walker, director of community relations for PK Management, which bought the building for $7.56 million in June 2012, said a team was on the ground to determine how to best fix Patten Towers.

Walker was unaware of the recurring emergency responses at the taxpayer-subsidized low-income housing project, but said the company maintained a "social service coordinator" on-site to help residents cope with nonemergency problems.

"If there is a problem, we're going to take care of it," Walker said. "We don't want a building that's not functional, especially not with the residents involved. We take pride in what we do."

As of Wednesday afternoon, residents were told it could be three to five days -- perhaps longer -- before they can return to their homes.

Many face uncertain futures.

"We don't know which way we're going," said Willy Whaley, 69, who stayed at the Brainerd Recreation Center on Tuesday night. "Hopefully we're going to try to get back in a couple of days. I don't know what to do."

He said he's thankful the fire was contained quickly.

"I'm just glad we didn't get burned up," Whaley said.

Whaley and others were allowed back in the building Wednesday morning to gather a few belongings.

Many walked out wheeling suitcases, clutching plastic bags or tote bags to bring back to the recreation center or East Brainerd Church of Christ.

At the shelters, the Salvation Army provided food and spiritual care while the Red Cross focused on shelter and physical needs.

"We're prepared to stay as long as we're needed," said Kimberly George, director of development at the Salvation Army.

On Wednesday evening, as residents recuperated at their new homes, an ambulance followed by a city firetruck arrived at the Brainerd Recreational Center to answer an apparent call for help.

A policeman waved his arms at the arriving fire truck to signal a false alarm.

Contact staff writer Ellis Smith at esmith@timesfreepress.com or 423-757-6315. Contact staff writer Beth Burger at bburger@timesfreepress.com or 423-757-6406.