Fire investigators say a Wednesday night fire at 409 Olive in Hannibal is accidental.

Hannibal Fire Department investigators say an occupant of the residence was working on a moped engine in the basement when the fire broke out. The house sustained heavy smoke and fire damage. Flames were brought under control in about 15 minutes. The alarm came in at 11:03 p-m. Fire crews were on the scene for about two hours to conduct salvage and overhaul operations. The occupant and pets escaped. No injuries are reported.