Hilltop heat in the 80s and breezy conditions with 5 mile-an-hour winds helped fuel a fast-moving fire Thursday evening that prompted hasty escapes and evacuations and destroyed four condo units and damaged two others in the Gibbs Ranch Villas, a Cal Fire commander said Friday.

The gated community with one way in and one way out is surrounded by acres of flammable oak woodland and chaparral species that carpet the steep hillsides above and below, the same brush-covered hillsides that border multiple neighborhoods from Gibbs Ranch to Sonora High, Woods Creek and Dragoon Gulch.

But the destructive blaze, which displaced 20 people from their homes in the 14-unit condo building and injured one firefighter overcome by heat and dehydration, was not a close call or a near-miss for other nearby neighborhoods and the rest of Sonora, Division Chief Jeff Sanders said.

“The heat and humidity did contribute to firefighter fatigue,” Sanders said, “so we called in more engine crews and rotated personnel in to counter that.”

A total of 35 firefighters and five command staff with 14 engines, including type one urban engines, type three vegetation engines, and a ladder truck from Tuolumne Rancheria Fire Department responded to the blaze reported at 5:50 p.m. at 19849 Villa Road.

Firefighters dressed for structure protection toiled in 65 to 70 pounds of flame-resistant gear with breathing apparatus and tanks weighing more than 25 pounds each strapped to their backs.

Sonora City Fire, Tuolumne County Fire and Cal Fire first dispatched urban structure protection crews and wildland fire crews, four aircraft, and a bulldozer to be prepared if the fire began to spread from the burning building to adjacent vegetation close by, Sanders said.

“On initial dispatch right now we always plan for wildland fire,” Sanders said. “The first units on scene, they contained it to the structure. They cancelled the wildland firefighters, the aircraft and dozer.”

The weather cooperated to an extent, in that it could have been even hotter and windier, Sanders said. Breezy conditions kept fresh oxygen on the fire but winds were not strong enough to throw showers of embers great distances from the burning building.

Don Smith, president of the homeowners association at Gibbs Ranch Villas, said a lot of oak, manzanita, buckbrush and other brush was cut back away from the rear of the 14-unit condo building a month ago, creating an additional clearance of 150 feet from the building to edges of fuel-carpeted slopes that extend east and north toward Sonora.

Smith emphasized access roads for the climb up to Gibbs Ranch Villas are wide but the hilltop neighborhood was built 45 years ago on a cul-de-sac. Sanders said the roads up there are built to code for firefighting responders, and crews had zero issue getting access to the incident Thursday evening.

“We were lucky they were able to contain it,” Smith said Friday out front of the burned section of the condo building. “And that’s nobody’s hurt.”

Stacy Hames said she was home in Unit 105 on the ground floor when she saw smoke coming across her sliding glass door, and “crackling fire” with flames on the back deck next door. She grabbed her dog Buffy and got out before deputies and firefighters came door-to-door to clear the building of residents before they started fighting the blaze.

“I think it originated upstairs and next door to us,” Hames said. She and her husband Rich Henderson, who just moved to Tuolumne County on April 1, were among those displaced by the fire and they said they planned to stay Thursday night at their cabin in Cold Springs.

Henderson was outside the fire-damaged condo building Friday and he and other residents said they understood undamaged units have had electricity and water restored, and they were waiting for gas service to be evaluated. Sanders said six units, four destroyed and two damaged, are unsafe to occupy, and residents of the eight undamaged units will likely be able to return to their homes.

Debbie Calcote with the Gold Country Region American Red Cross said Friday the displaced -- 17 adults and three children -- were assisted by a dozen Red Cross volunteers. Most had places to stay with family or friends. Three stayed in local hotels, Sanders said. Red Cross volunteers remained on scene at Gibbs Ranch Villas until 2 a.m. Friday, when the last of the displaced residents’ relatives came to get them.

Insurance representatives and utility workers were at the scene later Friday, as well as a security specialist who said he was hired by the homeowners association.

Sanders said the point of origin for the Thursday evening fire was inside one of the units and the cause of the fire was being investigated. The Sheriff’s Department, citing Cal Fire, said the fire started in Unit 108.

Contact Guy McCarthy at gmccarthy@uniondemocrat.com or 588-4585. Follow him on Twitter at @GuyMcCarthy.