A 4-year-old boy is recovering in the hospital after he fell down an elevator shaft in Brooklyn Wednesday night.

It happened around 8 p.m. inside a building located at 841 Union Street near 7th Avenue in Park Slope.

Police say the boy was in the elevator with his parents when he fell about 50 feet to the ground.

It's not clear what led to the fall, but police say it appears to be a freight elevator with large gaps between the wall and the floor.