Witness Rafael Gonzalez, who lives in a building across the street, told WCBS-TV he was woken by the smell of smoke and then saw some people using a fire escape of the burning building as the fire raged.
Luz Hernandez told the New York Times that her fourth floor apartment had filled with thick smoke. She said she escaped through a fire escape with her husband and two sons as the smoke continued to rise around them.
The building contains more than 20 flats and was built just over 100 years ago.
The Associated Press said the fire was the deadliest in New York - excluding the 9/11 attacks - since 87 people died at a social club in the Bronx in 1990.
Earlier this month, a mother and her three children died in a fire at their home in Brooklyn, New York. Sky more