Firefighters in Altoona worked overnight putting out hotspots at an empty building.
The fire broke out just after 10:00 p.m. Thursday at 109 Eighth Street Southeast, near the Hy-Vee.
Flames were shooting out of the roof when fire crews arrived. The fire was knocked down somewhat quickly, but crews were still putting out hot spots until at least 1:00 a.m. Friday.
The cause of the fire is still being investigated.