Woman mourns loss of identical twin sister after fire, possibly tied to propane heater, at homeless camp off China Hat Road

(Update: Adding video, comments by fire victim's sister, Bend Fire official)

BEND, Ore. (KTVZ) -- Colleen Carroll is mourning the loss of her identical twin sister, Courtney Carroll, who died recently at St. Charles Bend, a week after a fire hit her homeless camp on China Hat Road, south of Bend.

"I don't think it has hit me yet -- she was my identical twin," Carroll told NewsChannel 21 on Monday.

She said Courtney had been living in what Colleen described as a "box hut" she had built.

Colleen, who lives in Humboldt County, California, says her sister suffered severe injuries after a space heater called a "Mr. Heater Buddy" exploded.

Bend Fire & Rescue responded to the call, as they do other blazes on U.S. Forest Service land near town.

"The fire was quickly extinguished," Deputy Fire Marshal Cindy Kettering said. "It was a relatively small fire, and on investigation, we did find a number of potential causes within the debris, and the fire (cause) remains undetermined."

Kettering said because other combustible items were found at the scene, investigators could not determine the space heater was responsible.

But Colleen Carroll said she has no doubt about the cause and that the injuries her sister suffered point to an explosion.

She said her sister had been living on China Hat due to a previous fire at her home.

"Grandma and Grandpa take care of her son. She left -- she has an 11-year-old," Colleen said. "She's been doing the best she can to get out of that situation, but she doesn't have any family there."

Despite the officially undetermined fire cause, as temperatures drop, Bend Fire's Kettering has recommendations for how to safely use a space heater.

"We want people to have good clearance around those space heaters -- not putting things like blankets or bedding around it, particularly, not having it next to any sort of furniture -- just keeping it a good three feet away from any of that material," she said.

Courtney's sister said the space heater was given to her by someone who got it from a Bend nonprofit. Reach Out Central Oregon said they handed out heaters last year and in years past, but did not hand one out to Courtney.