A family is grieving the loss of a 1-year-old boy killed after a fast-moving fire ripped through a Bronx apartment building Monday.

Flames broke out on the second floor of the five-story building at 2609 Bainbridge Ave., between East 193rd and 194th streets, in the Fordham section at around 3:40 p.m.

Emergency responders transported Kwesi Harris’ three children to the hospital. His son, Liam, was pronounced dead. His twin children, both 6 years old, are still in critical condition. 

“I’m just crying,” Harris said. “I’m just holding on and being strong because I know my family is supporting me.”

What happened? 

The FDNY said the flames spread quickly from the second to the third and fourth floors as residents rushed to evacuate.

At one point, firefighters had to perform a roof rescue, pulling residents out of windows. Fire officials said 80 firefighters and EMS personnel responded to the scene,

Two adults and two firefighters had non-life-threatening injuries. 

The Red Cross is helping at least 38 displaced residents. The cause remains under investigation.

Fire may have been exacerbated by open doors

Fire officials said they believe the flames were spread after tenants left doors open.

This building has three open violations from 2014 to “replace or repair” self-closing doors that are missing or defective, according to the city’s Housing Preservation and Development. 

The FDNY has been urging residents in apartment buildings to be vigilant and close doors, as there have been multiple deadly fires over the past few weeks. 

“We’ve had several of these fires lately where the occupants of the fire apartment have fled the building and left the apartment door open. That appears to be the case here again, because of the heavy amount of fire that we found in the hole we on arrival,” said Malcom Moore, FDNY assistant chief of special operations.

He, again, stressed the importance of shutting doors.

“It’s tough to wrap your mind around having to do that. But the minute you close that door, you give everyone else in the building an opportunity to flee. And you give yourself more time to flee by not allowing the fire to chase behind you,” Moore said.  

More from CBS News