A downtown Madison apartment was ruled uninhabitable after a fire Monday. Firefighters were sent to the 100 block of South Hancock Street at around 10:25 a.m. A resident reported hearing a smoke detector and finding smoke coming from an upper floor. All occupants who were at home at the time of the fire but evacuated safely and no injuries were reported. Crews arrived on the scene at around 10:30 a.m. and found heavy smoke and fire coming from the back of the building. The fire was initially knocked down at 10:37 a.m., but flames had spread to the attic and firefighters continued to work in that area for an extended period of time. Officials said the entire-three-unit building is uninhabitable because of the extent of the damage. The American Red Cross is assisting the displaced occupants. The cause and origin of the fire remain under investigation.