NEW YORK (CBSNewYork) — Investigators say a space heater is to blame for the fire that ripped through a Lower East Side high-rise on Wednesday.

Six people suffered minor injuries in the three-alarm fire at 89 Columbia Street just north of Delancey Street.

Officials say the fire started inside apartment 16-D and then quickly spread to the apartments above.

More than 100 firefighters responded to the scene and got the blaze. Four firefighters and two civilians were treated at Bellevue Hospital for smoke inhalation.