A 3-year-old boy died Sunday in a blaze that quickly consumed a three-story apartment building in the Grand Crossing neighborhood, neighbors and fire officials said.

The boy’s parents were not home when the fire started about 10:30 a.m. at 1421 E. 67th Pl., according to Chicago Fire Department spokesman Larry Langford.

The Cook County medical examiner’s office identified the 3-year-old boy as Maqkwone Jones. Authorities had initially said the boy was 4.

The fire seemed suspicious enough for CFD to turn the investigation over to the Chicago Police Department, Langford said. Police could be seen Sunday night roaming an alley behind the charred remains of the building.

Ashes, debris and broken glass littered the ground out front. One neighbor, Karen McClenden, said the fire consumed the building in 10 minutes.

“That building was in flames,” she said. “Really bad flames.”

Another woman, who lives about a block away, said the smell of smoke made its way into her apartment.

The woman, Ebony Braithwaite, described seeing “big, darkish, grey smoke just shooting toward the sky.”

Others in the neighborhood said flames filled the building.

Fire crews arrived 10:30 a.m. and a squad of roughly five firefighters rescued the child, officials said. Langford said the boy was in cardiac arrest, a common result of heavy smoke inhalation.

The boy was taken to Comer Children’s Hospital, where he was pronounced dead at 11:36 a.m., according to authorities.

An autopsy Monday did not rule on the cause and manner of his death pending further investigation, according to the medical examiner’s office.

The Department of Children and Family Services also visited the scene of the fire to investigate, police said.

Shortly after the rescue, the three floors of the porch area collapsed into one another, Langford said. It took just over an hour for firefighters to put out the blaze.

Two other people, including a firefighter, were also injured, according to Langford.

An adult was treated for smoke inhalation. The injured firefighter suffered heat exhaustion and was taken to Northwestern Memorial Hospital for minor injuries, Langford said.

Contributing: David Struett