A 3-year-old boy plunged to his death from a 13th-story window Sunday after he pushed out a window guard at a Harlem housing project.

Around 7 p.m., Latyr Sene fell from his parents' apartment in the Harlem River Houses II complex on Frederick Douglass Boulevard and 152nd Street, according to police. Sene landed on the ground below, and was rushed to the hospital in cardiac arrest. He was pronounced dead on arrival at 7:30 p.m., police said.

Witnesses told Channel 4 that they saw the boy in the window before the fall.

"The boy was laying on the ground in the dirt. Just still. He fell. We heard the big bang, and we looked outside the window. He was on the ground," witness Annette Aiken told NBC New York.

"It was very loud and I thought the air conditioner fell, but it wasn’t the air conditioner. It was the boy hitting the air conditioner on the way down," Aiken, 47, told the New York Daily News.

Sources told the New York Post that bars were supposed to be secured in place outside the window. But the bars were loose, and the boy had easily pushed them to the ground. According to the Daily Mail, someone in the apartment moved an air conditioning unit and failed to screw the bars back in properly.

The boy's parents have been identified as African immigrants. They were taken away by an EMS supervisor after an ambulance carrying their son left. According to the Daily Mail, they have since been taken to the NYPD's 32nd Precinct, but have not been charged.

It's unclear what the parents were doing at the time of the fall.

Renee, a ninth-floor resident, told the Post that the boy's mother, Annette, came running outside with Latyr's twin brother after learning what happened.

"The mother had the other twin in her arm,” she said. “My knees buckled. I couldn’t bear to look out the window. I ran downstairs [and] the fire department was trying to revive him and I just totally lost it."