NEW YORK — A 3-year-old boy died Saturday morning after falling from a 29th-floor balcony of an apartment building in New York City, police said in a preliminary investigation.

Officers found the injured toddler lying on scaffolding on the 3rd floor after receiving a 911 call at 11:09 a.m. The boy was taken to a nearby hospital where he was pronounced dead.

“We believe the child exited through a window, but exactly how it happened is under investigation at the time,” a police spokesperson told The Associated Press. The apartment is located in the Taino Towers residential complex in Harlem.

New York City law requires owners of buildings with three or more apartments to install window guards if a child age 10 or younger lives there or if a tenant or occupant requests them. It is unclear if window guards have been installed in this particular apartment.

The spokesman said the child’s death was under “active investigation” and police were speaking with two people who were inside the flat when the boy fell.

Nidia Cordero, who lives on the 34th floor of the building, told the New York Post that she suddenly heard what she believed to be the child’s mother screaming.

“And I looked,” she said, “and the baby was in the scaffolding.”

Richard Linares told the New York Daily News he was outside the apartment complex when the toddler fell.

“We heard a big bang,” he said. “My boy who was here ran forward. He ran to the scaffold to find the baby. The baby was crying and still breathing when he arrived.”

He later added, “By the time the paramedics got him down, they had a towel over his face.”

Tanjelyn Castro, a neighbour, described to the Daily News a frantic scene as police and locals tried to reach the child.

“Everyone who was outside was running, climbing,” she said. “Every man you saw was trying to reach the scaffold. It was a whole bunch of emotions.”