A cigarette is to blame for the fire that left two families homeless in Mount Vernon Wednesday.

The homeowner, who lives on the first floor, says it is the second fire in 13 years at the house on South 11th Avenue. Fire officials say the third-floor tenant called after he smelled smoke around 10 a.m. More than 20 firefighters battled the flames. Only one person was home at the time and no one was injured.

Two of the four families that live in the home cannot return due to the damage. One tenant says he will stay with relatives while others will be helped by the Red Cross. Investigators determined that a lit cigarette thrown out by the third-floor tenant blew back in and started the fire.