"When I wake up, all I see is the flames going up, kids are on the fire escape", said neighbor Rafael Gonzalez.
De Blasio confirmed his death on Saturday. The Fire Department of NY said earlier that 15 people were seriously injured in the fire near the Bronx Zoo Thursday night.
New York City is going through a bitter cold snap with temperatures in the low-teens Fahrenheit (minus teens Celsius) and high winds.
When the mother fled the burning apartment with the boy and his 2-year-old sibling, she made a fatal mistake - she left the apartment door open.
Kwabena Mensah said his son, Emmanuel, spent his final moments trying to rescue other people in the building.
D&E Equities said through spokesman Ronn Torossian that it is communicating with the city about the Thursday fire in the Bronx.
About 170 firefighters are at the five-story, walk-up apartment house.
Torossian also said the company's prayers and thoughts are with the families.
Officials found the victims, one of whom was 1 year old, on various floors.
It was the city's deadliest fire in decades, excluding the September 11 terror attacks.
Batiz lost his sister, Maria, and her 8-month-old grandson in the Thursday night blaze. Stewart moved to the United States from Jamaica in the 1980s.
Fire Commissioner Daniel Nigro called the fire, "historic in its magnitude", because of the number of lives lost.
Hundreds Of Iranians Protest High Prices In Northeastern City Of Mashhad
The semiofficial Ilna news agency reported there were smaller protests in Neyshabour, Kashmar, Yazd, and Shahroud. Such mass protests without police permission are unusual in Iran and those taking part face arrest.
The father lives next door to the now non-existent building.
A family is still waiting to find out what became of a relative who was staying in a New York City apartment building where a fast-moving fire killed 12 people.
Twum Bredu (BREH'-doo) says Mensah had recently graduated from Army National Guard boot camp.
FDNY photos show ladders stretched to the roof of the five-story building. That allowed the blaze to spread quickly.
Nigro stresses the importance of closing doors to help contain fires.
A priest in the Bronx, New York, tended to grieving families and asked for prayers for them as well as for victims of a December 28 fire, one of the deadliest in New York City and the borough's history, which left at least 12 dead and many fighting for their lives.
His grieving father spoke to the NYPost and said that helping people was "in his nature".
The cause remained under investigation.
A 3-year-old boy's screams alerted his mother that a fire had erupted in their apartment in the building's first floor.
The dead, so far, include four children.
Tenants of the building, a mix of native New Yorkers and Latino and African immigrants, scrambled down fire escapes.