Careless disposal of a cigarette caused a four-alarm fire that devastated a Dorchester three-decker early this morning and left 13 people homeless, according to a fire official.
The fire started on the first floor front porch, then rose to the second- and third-floor porches of the three-decker at 46 Colonial Ave.
“It went up the front of the building engulfing all three porches and then spread into the house itself,’’ said Steve MacDonald, spokesman for the Boston Fire Department, who said a cigarette had caused the blaze.
Three firefighters who sustained minor injuries — shoulder, knee, and ankle-related — extinguishing the fire have been treated and released from area hospitals, Steve MacDonald said.
The fire was reportedat 1:41 a.m., MacDonald said. Two alarms were originally called, but the fire was upgraded to four alarms due to heavy fire in the front of the building.
“The whole front part of the house was on fire when we arrived on the scene,’’ MacDonald said. “We immediately ordered a second alarm. Because of the hard work of our firefighters, we went to four alarms. We needed to get enough manpower to extinguish it.’’
The heavy fire was put out in 30 minutes, but firefighters remained on the scene extinguishing hot spots and opening up walls until about 6 a.m., MacDonald said.
Residents of the apartment building evacuated safely with the help of working smoke detectors, reported the fire department’s Twitter account. MacDonald said the Red Cross was on the scene assisting the displaced.
Volunteers assisted eight adults and six children with recovery funds for food, clothing, jackets, and shoes, communications director for Red Cross Massachusetts Kat Powers said in an e-mail.
The MBTA provided a bus to keep people warm and dry while the Red Cross assessed their immediate needs. Emergency shelter in a hotel is also being provided.
A dog from the residence is being treated by a veterinarian.
The Boston Fire Department chief estimated $350,000 in damages for the affected apartments at 46 Colonial Ave., said MacDonald, with the majority of the destruction located in the front of the building.
The vinyl siding of a neighboring building, at 42 Colonial Ave., melted during the blaze, creating an additional $50,000 in damages.
MacDonald said the residents of 42 Colonial Ave. can enter their homes, but their electricity is currently out due to fire damages.