A house fire in Cambridge that left one man dead may have started when food was left unattended while cooking in the home’s kitchen.

The cause of last week’s fire on Queen Street East has not been officially determined, but the Office of the Fire Marshal says it is considered accidental and unattended cooking is the leading theory.

Rob Briere, 32, was killed in the fire. He lived in the home’s basement apartment, according to people who knew him, and was good friends with homeowner John Orth.

Orth was able to get himself, his wife and their daughter out of the house unharmed. After that, sister-in-law Darlene Keating says, Orth’s thoughts immediately turned to his friend in the basement.

“From what I understood, the windows exploded (and) he was unable to get his friend out,” Keating said Tuesday.

“He’s sad and upset, and wishes he could have done more.”

In the five days since the fire, there has been a significant amount of community support for Briere and the Orth family.

Two fundraisers have been set up online – one to help the Orth family, who lost all their possessions in the fire, and one to cover the cost of Brier’s funeral.

Flowers and other items have been left outside the house. Messages of love and support have been left on its walls.

“Ali and John are just overwhelmed with the outpouring of love and support that the community has shown them,” Keating said.

With reporting by Nicole Lampa