It's not known yet what caused a fire that left a Wilmington apartment unlivable Saturday afternoon. Crews arrived at 1 South Broom Street around 4:10 p.m. to find heavy smoke coming from a three-story apartment building above a convenience store. Firefighters were able to contain the flames to the apartment where the fire started, and the situation was under control in roughly 45 minutes. The building's residents got out safely by the time firefighters arrived, and no one was hurt. Licenses and Inspections has ruled the apartment where the fire started isn't fit to be lived in anymore. The city's Fire Marshal's office is investigating how the fire started, and there's no dollar amount of the damage yet.