74-year-old man on oxygen lights cigarette, dies in house fire

A 74-year-old man died Saturday after he caused a flash fire while lighting a cigarette inside his home in Isanti, Minnesota. 

The fire occurred around 6:18 p.m. at a home on the 5600 block of 263rd Avenue Northeast. According to the Isanti County Sheriff's Office, the victim tried to light a cigarette while using oxygen, causing a flash fire. 

When deputies arrived, the victim, identified as Lawrence Tuma, was already dead. The sheriff's office said he died of smoke inhalation. 

The fire remains under investigation by the Isanti County Sheriff's Office and the State Fire Marshal.