CONCORD, Calif. (KGO) -- Contra Costa County fire investigators are trying to determine the cause of a house fire this morning that killed one person.
Neighbors could only watch helplessly as a huge fire destroyed the home on Coventry Road at Clayton Road just before 6:30 a.m. One neighbor tried to get to the woman who lived at the residence.
"Somebody was trying to break in to get her out of there, but it just went. The shingles were broken, she had holes in her roof, it just went up like a tinder, it was awful," said Terri Otto, neighbor.
Gilberto Nanez lives across the street and took video of the fire. He couldn't believe the size of it.
"It was crazy. In front of my house it was warm," said Nanez.
Terri Otto was worried it would spread.
"I got my hose because embers were all up in the trees," said Otto.
Neighbors say one woman lived in the home. Firefighters say one person was killed in the fire and neighbors are assuming it was her, but investigators can't say for sure.
"That would always be the assumption that that's who it is, but we need to make sure before saying something definitively," said Robert Marshal, Contra Costa County fire marshal.
When firefighters got there, fire was coming from all sides of the home. The roof was starting to collapse and power lines were down. Getting to the home was a challenge and dangerous.
"The roof collapsed into the structure, so there is a lot of debris. There are a lot of belongings that are still smoldering, so we are still trying to get this completely out," said Marshal.
No firefighters were injured battling the blaze. Investigators believe the fire started in the middle-back of the home, but the cause has not been determined.
1 person killed in 2-alarm house fire in Concord