The couple told police they arrived at their Des Moines home around 8 p.m. Sunday and discovered someone had turned on the burners of their gas stove and placed a roll of paper towels on the surface, The Des Moines Register reported Monday.
The homeowners said there was smoke, but no flames. They turned off the stove and removed the paper towels before leaving the house again to go to the store.
The couple said they returned about 15 minutes later when they realized they had left a wallet behind, and they discovered the house was filled with smoke with a roll of paper towels placed on the same two lit burners.
Firefighters responded to the home about 8:40 p.m. and extinguished the flames.
The couple said they couldn't think of anyone who would want to start a fire in their home and police have not identified any suspects.