A fire that killed a 63-year-old man in his northeast Minneapolis home last week was caused by unextinguished cigarettes that ignited a sofa in the living room, fire officials said Thursday.

Thomas E. Nowak died late Saturday from injuries suffered in the fire in his home in the 1100 block of 23rd Avenue NE.

The fire, which was contained on the first floor and reported about 6:15 p.m. Saturday, was extinguished within about 20 minutes. Firefighters found Nowak while searching the second floor. He was taken to Hennepin County Medical Center, where he died.

Nowak’s death was the first fire fatality of 2018 in Minneapolis.