Fort Collins Apartment Fire Ruled Accidental

FORT COLLINS, Colo. (CBS4) - Investigators have ruled that a three-alarm fire at a Fort Collins apartment complex on Tuesday was accidental.

The fire started just before 4 a.m. Tuesday in the Buffalo Run apartments, located at 1245 East Lincoln, just east of Old Town near the intersection of East Lincoln Avenue and South Lemay Avenue.

Firefighters said there are 24 units in the building and that about half were damaged by the flames or by water damage. Officials with the American Red Cross said 37 people were displaced.

PHOTO GALLERY: More Images Of The Fire

"We looked out and there were 20 foot flames coming out," said Isaiah Lucero, a witness.

Investigators said the fire was caused by someone not properly disposing of a cigarette.

"We had heavy fire involvement that extended up from the second floor to the third floor and into the attack," Poudre Fire Authority Battalion Chief Jim Pieterangelo said.

Matt Erwin and his girlfriend live in a nearby unit from where the fire started.

"I immediately went in with a fire extinguisher and tried to extinguish the fire but at that point the whole bedroom wall and the roof just pretty much were fully involved in flames," Erwin said.

When he couldn't control the flames, Erwin started waking up his neighbors.

"I was breaking down doors down with the fire extinguisher. If the door was locked I just busted it in to make sure there was nobody inside," he said.

Despite the massive damage to the building no one was hurt.