AUSTIN — Authorities are investigating a Christmas Day house fire in Austin that left one person dead.

Austin Fire Chief Jim McCoy said the fire was reported just after 3 p.m. Friday. The victim was found dead inside.

Nobody else was home at the time of the fire. The Mower County Sheriff’s Office said flames were just starting to come out of the windows in the front room when firefighters arrived.

The fire department said the victim was a woman who lived alone. Her name has not been released pending an autopsy and notification of relatives.

The cause has not been determined.

Fatal fires have spiked in the state this year, killing at least 52 Minnesotans compared with 44 in 2014, according to data from the state fire marshal’s office.