A 4-year-old boy has died in West Harlem, and police are investigating the circumstances surrounding his death.

Emergency service units arrived Monday morning with full gear at an apartment building on Adam Clayton Powell Jr. Boulevard where the scene was still active.

Police say they received a 911 call before 8 p.m. on Sunday about an unconscious child. According to the NYPD, officers found the boy unresponsive inside the apartment.

EMS rushed the child to Harlem Hospital where medical staff tried to save him. The boy was pronounced dead shortly after arriving there.

Investigators have since been canvassing the building and surrounding neighborhood for more details about what led to the boy's death.

"I heard about it this morning. My sister came by and said something happened around the corner. I didn’t know what it was," said Harlem resident Violet Palmer. "Someone said a child died. That's horrible. I just want whoever did that to that lil' boy to get what they deserve."

Sources close to the investigation say the boy appeared to be malnourished. A person of interest has been taken into custody, but police are still working to determine the exact cause of the boy's death.

The NYPD is withholding the child's identity while notifying family members.