The Missoula Fire Department responded to a structure fire on the 900 block of Stoddard Street on Tuesday afternoon.
Right now, the cause is unknown, Missoula Fire Department Assistant Fire Chief Brad Davis said at the scene.
Some bystanders reported hearing an explosion, although Davis said he had no information about an explosion.
Gayle Collins lives behind the residence and called 911 after she saw the flames and smoke.
She said she heard an explosion that knocked things off of her windowsill, and ran outside and saw smoke and flames she estimated were about 10 feet high.
“It just happened so fast,” she said.
Davis said there were no injuries known at the time, and the fire department was still working to clear the house as of press time.