A man killed in a house fire Saturday in Isanti has been identified as Lawrence Tuma.

Deputies went to a home on the 5600 block of NE. 263rd Avenue about 6:18 p.m. on a report of an unresponsive man inside a residence. They found there had been a fire in the home and Tuma was dead, according to the Isanti County Sheriff’s Office.

Tuma died from smoke inhalation, the Sheriff’s Office said.

Preliminary information indicates that Tuma attempted to light a cigarette while oxygen was being used in the home, and that sparked a “flash fire,” the Sheriff’s Office said.

The fire remains under investigation.