Fire investigators are looking for the cause of a Friday morning fire in a Hannibal duplex.

Hannibal Fire Chief Sean Hampton says the alarm came in at 8:03 a-m. Firefighters arrived at 556 Virginia Extension to find flames coming from the front windows of the south apartment. A smoke alarm alerted the only person in the building to the fire and the resident escaped through the back door. There is smoke damage throughout the building. Fire crews knocked down the flames in 10 to 15 minutes. No injuries are reported.