The sudden sound of a gunshot in a Far South Side home apparently led to a terrible discovery Sunday — a 3-year-old boy, fatally shot in the face.

Now Chicago police say they are looking into the “devastating” shooting in the South Deering neighborhood that appears to have been an accident. Although police identified the boy as a 3-year-old, there was some discrepancy among neighbors and bystanders as to whether he was 3 or 4.

Chicago Police Department spokesman Anthony Guglielmi released details of the shooting on Twitter. He said the boy’s family told police “they heard a gunshot while in another room and found their child with a gun.” The family’s home is on the 9600 block of South Escanaba Ave.

The boy was pronounced dead at Advocate Trinity Hospital, police said. The boy had been taken there by his parents, Guglielmi told the Sun-Times. The shooting happened around 4:15 p.m on the 9600 block of South Escanaba Ave.

Authorities did not immediately identify the child by name Sunday night. Guglielmi said detectives would continue to investigate the case, and so would the Department of Children and Family Services.

DCFS spokesman Jassen Strokosch said the agency had conducted a previous investigation involving the boy and one of his grandparents. However, Strokosch said that investigation did not involve the boy’s parents.

Police could be seen Sunday outside the family’s home, which had been marked off with yellow tape. A neighbor who did not want to be identified said it’s unusual for such a scene to play out there.

“Once in a great blue moon something might happen,” the neighbor said. “This is, like, that blue moon.”

At Advocate Trinity Hospital, where the boy was pronounced dead, a car believed to be the one parents used to transport the boy to the hospital was surrounded by yellow tape and later towed.

Anti-violence activist Andrew Holmes, who was on the block where the shooting occurred, said he expected police detectives to release additional information Monday. “You’ve got to find out where this gun came from or who it’s registered to,” he said.

In the meantime he used the occasion to advocate for gun safety.

“Go through your homes and move these guns,” he pleaded.

A 2016 USA Today and the Associated Press analysis of accidental child shootings across the country found that most such shootings in Illinois occur in Chicago but also mostly involve teenage victims. More than half of the shootings occurred at the child’s home or another residence.

Still, the study found that Illinois had the 29th highest rate of accidental child shootings, coming in just below the national average.

Contributing: Justin Jackson, Jermaine Nolen and Tom Schuba