The Thomaston Fire Chief says a fire that destroyed an apartment building and left at least a dozen people homeless was started by a carelessly disposed cigarette.The fire on Sunday started on the top floor of the building on Knox Street.Chief Mike Leo says a tenant tossed a cigarette in a plastic container, went to take a shower and when he came out, found one of his walls on fire. Leo says 15 or 16 people lived in the 11-unit building. About half of them were home at the time. Leo says one person had to jump off the second floor to get out and was treated at the hospital for minor injuries. The Red Cross is helping the families while they find new places to live.