NEW YORK (CBSNewYork) — Investigators Saturday morning were trying to determine how a 3-year-old boy died in a Bronx apartment overnight.

As CBS2’s Ilana Gold reported, police had numerous questions Saturday morning about the death of Poseidon Quinones, who lived in an apartment on East 163rd Street near College Avenue in the Melrose section of the Bronx.

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Poseidon’s grandmother found him unresponsive when she went to check on him in bed around 1:45 a.m. She called 911, and Poseidon was rushed to Lincoln Medical and Mental Health Center where he was pronounced dead, police said.

Police said Poseidon had bruises on his body that are considered definite signs of trauma.

As of mid-morning Saturday, police did not know how the bruises got there.

Police told 1010 WINS Poseidon’s grandmother also found vomit in his mouth.

A neighbor said the grandmother claimed the boy was sick all day Friday and fell out of bed.

“They rushed him to the ambulance. There was no movement in the body; no life. They were pushing down on the body; he was very still,” the neighbor said. “And the grandmother said she didn’t know it was such a serious thing; she knew he was throwing up all day; he was sick, but he had no fever.”

But circumstances remained unclear Saturday, and people who live in the area were in disbelief.

“Around 2 o’clock, we heard a big, loud scream and didn’t know what it was,” neighbor Luis Ramos said.

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Rashida Muhammad lives next door to the family and watched on as emergency crews arrived.

“By the time they got him to the ambulance, he was already gone. They were trying very hard to revive him but I could see in the ambulance that his body, it didn’t move,” she told CBS2’s Don Champion.

“I think it’s terrible. I think it’s terrible. He was only 3 years old. Come on – who would do something like that to a 3-year-old?” one man said.

Sources tell CBS2 the grandmother took custody of the boy after children’s services took the boy from his parents because of neglect.

Investigators say there had been no problems with the grandmother.

Detectives were questioning her Saturday morning, as she was the only adult in the apartment when police arrived at the scene.

Later Saturday morning, a man who identified himself as Poseidon’s father was seen entering the 163rd Street building and exiting again in hysterics, Gold reported.

The New York City Medical Examiner’s office will conduct an autopsy to determine the exact cause of Poseidon’s death. As of mid-morning Saturday, no arrests had been made.

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