DUMMERSTON -- A Jan. 6 Dummerston fire that claimed the life of a father and son has been ruled accidental.

Vermont State Police say Russell Nutbrown, 90, and Barry Nutbrown, 57, died in a fire "most likely caused by smoking materials."

"The preliminary autopsy indicates that both victims succumbed to smoke inhalation," State Police wrote Monday in a press release updating the week-old investigation.

Fire crews, including volunteers from West Dummerston, Putney, Guilford and Brattleboro fire departments, were called to the 420 School House Road residence before 5 a.m. Jan. 6.

Firefighters were able to contain the blaze, sparing nearby homes from damage. But the Nutbrowns were found dead inside the home.

State Police say they responded to the scene soon after the blaze was reported. The probe was handled by detectives from the Vermont State Police Fire Investigations Unit and Bureau of Criminal Investigation.

"The investigation has not indicated any signs (that) this fire was suspicious in any way," police said Monday.

Mike Faher can be reached at mfaher@reformer.com or 802-254-2311, ext. 275.