A fast-moving fire at a Fountain home killed a woman who couldn't get out in time. The fire happened on the 300 block of Walbrach Way at about 5:30 on Monday morning.

Investigators are still working to figure out what happened, and they're teaming up with the Colorado Bureau of Investigation to try to get to the bottom of it.

Police say a preliminary investigation has determined that the fire started outside of the home, and spread incredibly fast.

"I came running out here, and sure enough, the whole underside of the eve, that whole corner of the house was on fire," said next-door neighbor John.

When the flames shot up, neighbors called each other and tried to help.

"I grabbed my hose, and turned it on," said John. "And by the time I got back to that side of the house, the whole side of it was just totally engulfed."

It spread so fast that firefighters from a station just two minutes away were not able to save the only person inside. "This was a very fast moving fire," said Fire Chief Darin Anstine, of the Fountain Fire Department. "Went very fast, and a lot of heavy damage."

Firefighters weren't even able to get into the house at first because of the flames.

"I couldn't get within 30 feet of the house, the heat was so intense," said John.

By the time firefighters did get inside, they found the 83-year old victim in the second-floor hallway.

"We believe that she was trying to get out, and maybe became overcome with smoke," said Anstine.

Fire officials say the family is devastated, and so are the men who responded. "The whole fire department is really sad about this one," said Anstine.

The home is completely destroyed, police tell 11 News that the victim lived in the home with her daughter and grandson, and that they were both at work when the flames erupted. The family has been contacted by El Paso County Victims' Advocates to help them.

Fire officials say they expect to have the investigation completed by Thursday of next week.