Heater was on for days: FDNY

The space heater suspected of sparking Sunday’s deadly Bronx apartment building blaze was left on for days, FDNY sources said.

The apartment where authorities said the fire started, killing 17 people, actually had multiple space heaters, sources said.

Fire officials have said the horrific blaze at 333 E. 181st St. originated with a heater in unit 3N, sending deadly billowing smoke throughout the 19-story high-rise.

Mamadou Wague, the dad of the family living in apartment 3N, denied to The Post on Tuesday that any of their space heaters were left on so long, saying they were only turned on at night.

“No, not many days. Nighttime. When we wake up, everybody goes out of the room, and we turn off the heaters,” he said. “Sunday it was still on because we didn’t wake up. We were still sleeping.”

An official investigation into the blaze is ongoing.

The developments come as a report surfaced Tuesday over another fire at the building years ago — which exposed several challenges to fighting a fire at the high-rise.

A compactor fire at the building on March 2, 1986, was cited in an article in WNYF magazine, the Fire Department’s training publication.

“The building, familiar to these firefighters, is thought of as a typical housing project where the report of smoke on one floor or another is handled as routine using the department’s standard operating procedures,” a 1986 edition of WNFY said.

“However, in firefighting, nothing is routine and on this day, once again, ‘Murphy’s Law’ reared its ugly head,” the magazine continued.

Among the obstacles faced during that fire was limited access to duplex apartments on six floors and “interior halls [that] are windowless and have no access to the exterior,” according to the article.

It said the building’s safety features “should have provided protection against fire but instead played a major role in its spread.”

No one was seriously injured in the 1986 blaze, in contrast to Sunday’s fire, which killed 17 and injured dozens of others.

FDNY Commissioner Daniel Nigro said Monday that smoke spewing through an open door in unit 3N was responsible for the deaths and injuries.