The fire that killed three people in a Corvallis apartment building early Monday morning has been ruled by fire marshals and investigators as arson, and a homicide investigation is underway.

Ravalli County Sheriff Steve Holton provided details after originally classifying the fire as suspicious in nature due to the time and location of the fire’s origin.

“By yesterday afternoon we had called in a professional fire investigator that we hired to help us with it,” said Sheriff Holton. “We called in four different state fire marshal investigators to help determine the cause and by yesterday afternoon we were able to say that this was certainly an arson fire and that’s why we started the homicide investigation and that’s what we’re working on today.”

Although three lives were lost in the fire on Monday, Holton said heroic efforts by first responders saved many more lives.

“Deputy Sheriffs and firemen did an outstanding job and probably saved anywhere from 16 to 20 lives getting them evacuated from the apartments they could get to,” he said. “One adult woman actually jumped out of a window and she is hospitalized now with very significant burn injuries, as well as injuries from the fall, but she was the only survivor of those upstairs apartments.”

Holton is asking residents and business owners in the area for help in trying to identify the suspects in the fatal arson fire.

“What we’re really asking for now is for anybody living in the Corvallis or Hamilton area that have surveillance or security cameras if they could contact my office at 363-3033 and just let our people know that they have it and identify themselves so we can reach out. The biggest thing now is to trying to identify any suspects.”

Holton said the three fire victims have not yet been identified due to the effort underway to notify all their family members.

The apartment building is a total loss.