NEW ROCHELLE, N.Y. (PIX11) — Police in Westchester County are investigating after a 4-year-old boy was found unconscious outside of a residence. Detectives believe the boy fell from an unknown height July 8.

According to the New Rochelle Police Department, the boy’s parents told officers at their 5th Avenue apartment complex that the boy was missing. When officers searched for him, they found the child behind unconscious behind the building.

Officers rendered first aid on scene. The 4-year-old was transported to a nearby hospital afterward, where he was listed in “critical but stable condition.” Police did not know the extent of his injuries.

The boy’s parents are cooperating with the investigation, police said.