Fire officials say arson is the cause behind the deadly weekend that weekend blaze that killed five people in Brooklyn.
Tests for accelerants were incomplete. But Fire Commissione Sal Cassano said accidental fires don't usually start at the front door of a building.
The fire department officially declared the deadly fire an arson Monday afternoon. and the city Office of the Chief Medical Examiner has labelled the fire a homicide.
"We're looking for anyone who may have been in the building, anyone who may've been walking by, who may have seen a car running a red light or someone carrying a strange object that night," said NYPD Det. Luis Yero, who is leading the investigation, on Monday.
The police want anyone with information to come forward and mindful of possible immigration status concerns, Det. Yero said "we are here to help people, not cause anybody a problem."
At least one resident of the burned building who survived came forward only to a local pastor. That minister brought the man to police, who took the information.
Four men and a woman, all Guatemalan immigrants, perished on Saturday in the fire at 2033 86th Street in Bensonhurst. The woman's 2-month-old daughter suffered a fractured skull after being tossed from a third-floor window of the burning building and landing on the ground.
Miraculously, the girl is doing well in the hospital.
"Doctors say the baby could make a full recovery," said Rev. Erick Salgado, who is supporting families victimized by the fire.
The baby's mother, was hailed as a hero, rescuing her kids before dying in the fire.
"Take care of the kids," said Luisa Ordoñez Chan, 33, said before disappearing forever into the raging fire and black smoke engulfing their third-floor Bensonhurst home, her husband Miguel Chan, 38, told the Daily News.
Chan and his wife were sleeping in their bed with son Josias, 2, and 2-month-old daughter Maria when the fire erupted. They scrambled to the window to save their children, handing them off to firefighters below. In the chaos, Luisa was unable to escape the blaze.
"Who would do this?" cried Miguel Chan, to the NY Post. "Why? Why her? I felt horrible that to save my children I had to [help] throw them out the window... I don't know if this was done by someone, but I hope the police find out if it was and capture the man."
The fire started around 2:30 a.m. and soon engulfed the three-story building on a busy commercial strip, consuming a ground-floor Japanese restaurant and two apartments on the upper floors.
The stairwell between the floors collapsed, as well as part of the roof, trapping residents, according to fire officials. The blaze was under investigation. Most of the building's residents were from Guatemala, neighbor Juan Gabriel told The New York Times.