Ninety-year-old Isa Degener survived a raging fire that ripped through her Waialua home in minutes Saturday, but she lost everything, including her reading glasses and hearing aid.

Degener, who is disabled, said the fire would have killed her if it weren’t for her tenants, Aubree and Kory Kocher, who dragged her out barefoot.

"They saved my life," Degener said by phone from Wahiawa General Hospital, where she was being treated for abrasions sustained during her escape. "I’m blessed."

Honolulu Fire Department Capt. David Jenkins said the fire started at 6:49 p.m. in the 68-600 block of Crozier Drive.

Thirty firefighters from nine companies responded to the two-alarm blaze, which destroyed Degener’s two-story home, but didn’t damage other properties.

Jenkins said the fire investigators were trying to determine the origin of the fire, which caused $490,000 in damage.

Degener, a retired botanist who specialized in Hawaii flora, lived alone in the house. Her husband, Otto Degener, an internationally known botanist, died in 1988.

The state Senate recognized the couple for their conservation efforts in 1979.

"I lost my memories," Degener said. "I’m still in shock."

She suspects arson and said she doesn’t understand how the home went up in just a few minutes.

"All the windows, from the roof all the way down, all the openings had showed the flames," she said.

Degener, who uses a chairlift on the stairs, said she was upstairs when she saw the smoke.

"It just started so fast I couldn’t make it," she said.

Kory Kocher, 37, came up the stairs and told her they had to get out, but Degener said she wanted to grab her purse.

"He didn’t allow me," Degener said. "He dragged me down like a bag of potatoes."

During their escape, Kocher stumbled on the stairs and fell backward into a wall.

"The smoke was very thick and we couldn’t breathe," she said. "I don’t know how we made it."

Aubree Kocher, 39, a piano teacher, realized something was wrong when she heard a fire alarm coming from her landlord’s home on the same property.

Kocher, who is also Degener’s caretaker, went to the home and upon entering it, found flames in the kitchen and heard screaming upstairs. She told her husband to rescue Degener from her bedroom.

Kory Kocher, a driver for Rolloffs Hawaii, ran up the stairs and found Degener inside her room, moving toward the exit. The room quickly filled up with black smoke, and Kocher grabbed Degener, who was moving too slowly.

Kocher, unable to breathe or see in the thick smoke, stumbled while carrying Degener near a turn in the stairwell. His wife guided him down the stairs and out of the house.

"I heard him stumble," Aubree Kocher said. "He was screaming for help."

Degener stopped on the lanai as Kory Kocher went to try to put out the fire with hoses, but flames began shooting out the doorway.

Aubree Kocher pulled Degener onto the lawn, and flames soon engulfed the house. There was also an explosion.

"I knew it was a lost cause," Aubree Kocher said, estimating the fire enveloped the home in about four minutes.

She recalled Degener saying: "It’s all gone … my house."

Waialua resident Sean Freiberg saw huge black plumes from his house about a mile away.

Freiberg, a former federal firefighter, drove to investigate and saw flames from the oceanfront home as tall as the tops of nearby coconut trees.

"It was just unbelievable," he said. "No question, there was no saving that house."