WHATELY — While an exact cause is unknown, a joint investigation by the state Department of Fire Services and the Whately Fire Department has concluded the Rainbow Motel fire early Saturday morning was likely accidental.

Department of Fire Services spokesperson Jake Wark said the joint investigation identified unit 10’s bathroom as the fire’s area of origin. The fire destroyed 10 of the 16 motel rooms, but all occupants made it out unharmed.

“Due to the extent of the damage, they were unable to make a conclusive determination as to the cause,” Wark said.

“They found no evidence of an intentionally set fire, however, and believe that it was accidental in nature.”

Fire Chief JP Kennedy said there were 17 people in the 16 motel rooms when first responders were dispatched to 68 State Road just after midnight on Saturday morning. Upon arrival, police officers reported the fire was fully involved and a defensive operation was initiated to stop the fire from spreading to six of the units. The scene was cleared at around 8 a.m.

Kennedy added it seemed like a “mix of longer-term residents and short-term renters” at the motel.

Through work with Amherst’s Community Responders for Equity, Safety, and Service (CRESS) Department, the Fire Department was also able to connect with the housing nonprofit Craig’s Doors, which eventually worked with the Red Cross to find housing in West Springfield.

“We really had a challenge finding housing for the 17 occupants who were displaced,” Kennedy said, adding that the University of Massachusetts Amherst’s commencement weekend made it difficult to find accommodations throughout the Pioneer Valley. “It was a really concerted effort with multiple agencies.”

During the fire, and while housing was being worked out, occupants were staged at Tom’s Long Hot Dogs across the street. Kennedy thanked the Police Department and Police Chief James Sevigne Jr. for their work in confirming that all the building’s occupants were out and brought to safety across the street.

“It’s a challenge when we arrive on the scene and we have that many people in proximity to a building that has heavy fire,” Kennedy explained, adding that in any fire scenario, people should get low, get out and stay out of a burning building. “The rate these fires grow at, it’s pretty unbelievable.”

Chandrika Patel, the longtime owner of the motel, which was built in 1953, declined to comment through her daughter.

While firefighters were able to save six of the motel rooms, which have no structural damage, they are currently not habitable because there is no electricity, water or heat.

Public safety agencies involved include the Whately Police Department, State Police, the South Deerfield and Deerfield fire districts, the Hatfield, Northampton, Conway, Williamsburg, Montague Center, Turners Falls, Greenfield, Hadley, Northfield, Bernardston and Erving fire departments, as well as South County EMS, the State Fire Marshal, the Department of Fire Services, the Hampshire County Sheriff’s Office and the Massachusetts Department of Transportation. Hampshire County TRIAD and the Red Cross were also on scene.

“Our dispatch center [Shelburne Control] did an excellent job getting resources out there in a timely manner,” Kennedy noted.

Chris Larabee can be reached at clarabee@recorder.com.