HARLEM, Manhattan — A 3-year-old boy is dead after falling out of an apartment building window in Harlem Sunday night.

Police say the child fell from a window in the Harlem River Houses II located at 2850 Fredrick Douglass Blvd., around 8 p.m.

Police sources at the scene tell PIX11 the victim and his twin brother were jumping on the bed in their 13th-floor apartment when the child fell.

The child was rushed to Harlem Hospital in traumatic arrest. He was pronounced dead when he arrived.

Sources say the family moved an air conditioning unit from one window to another and didn't screw the window guard back into the other window.

There is a heavy police presence in the vicinity of the apartment building.

PIX11's Magee Hickey and Myles Miller contributed to this report.