DULUTH, Minn. (AP) - A fire in a Duluth apartment tower has left one man dead.

Firefighters were called to the fire on the 13th floor of the Tri-Towers apartment complex about 4:45 p.m. Saturday.

Crews found a man unresponsive in the apartment and took him into the hallway to begin CPR. But attempts to revive him failed.

The apartment's sprinkler system knocked down the fire, and crews were able to extinguish the rest of the blaze.

Twenty firefighters responded. Damage is estimated at $12,000.

Authorities don't know what caused the fire. The Duluth Fire Marshal's office is investigating.