Brooklyn boy, 4, who fatally fell from apartment window was babysat

A 4-year-old boy who plummeted out the fourth-floor window of his family’s Brooklyn apartment was being babysat by his mom’s friend when he took the fatal plunge, a grieving relative told the Daily News Tuesday.

Little Jonathan Pierre’s mother left him in the care of a longtime pal visiting from Canada when she went to work Monday, according to the victim’s uncle.

“The mom was working but, you know, as a mom she was all the time calling, checking on the baby,” Jonathan’s uncle Mark Pierre told the Daily News. “That’s when the nanny said, ‘The baby has disappeared.’”

The frantic mom told her friend the boy had to be in the East Flatbush home somewhere.

“The sitter was saying she doesn’t see the baby,” the uncle said. “The mother says, ‘How come you don’t see the baby? Check the closet, look under the bed, look around!’”

“The mother said, ‘How far could [he] go?’” Mark Pierre said.

When Jonathan still didn’t turn up the panicked mother left work.

“She ran for home, tried to take a bus but took a cab because it’s faster,” the uncle said. “And then when she walked around she sees people screaming and taking a picture. She realized what happened.”

Minutes before 4 p.m., the boy had climbed out the fourth-floor apartment window on Farragut Road near New York Ave. and plunged to his death, according to police. The child was rushed to Kings County Hospital but couldn’t be saved.

On Tuesday, the boy’s shellshocked parents were grieving in the apartment where the boy tragically died.

The mother, who has one other child, a 22-year-old daughter, was inconsolable.

“She’s terrible,” the uncle said.

Though required child-safety bars appeared to be in the window, a Daily News reporter could see on Tuesday that they can be easily removed.

“Unfortunately it’s not really secure,” Mark Pierre said. “It’s not attached.”

On Tuesday afternoon, building workers screwed windows shut in common areas.

Marmarima Bah lives…