A malfunctioning space heater sparked a fire that filled a Bronx apartment building with thick smoke, killing 19 people including nine children Sunday in New York City's deadliest fire in three decades. Fire Commissioner Daniel Nigro said the fire "started in a malfunctioning electric space heater" in an apartment unit spanning the second and third floors of the 19-story building. The door of the apartment was left open, allowing smoke to quickly spread throughout the building, Nigro said. Some residents, trapped in their apartments, broke windows for air and stuffed wet towels under their doors. One man rescued by firefighters said he'd become numb to fire alarms because of frequent false alarms. Some residents "could not escape because of the volume of smoke," Nigro said. ------------------ For More News and Videos SUBSCRIBE and Turn Notifications On https://bit.ly/2r0BEND Get a Digital Subscription to the Tampa Bay Times https://bit.ly/2Xinunj Follow us: Facebook ► https://www.facebook.com/tampabaycom Twitter ► https://twitter.com/TB_Times Instagram ► https://www.instagram.com/tampabaytimes #NewYork #NY #Bronx