A three year old boy was found dead inside his Bronx apartment, cops said.

Little Poseidon Quinones was put to bed inside the Soundview apartment on East 163rd Street and Teller Avenue around 7 p.m. Friday, according to police.

But when his grandmother went to check on him around 1:40 a.m., he was unconscious and unresponsive, cops said.

She dialed 911 and emergency responders rushed him to Lincoln Hospital where he was pronounced dead on arrival, authorities said.

The boy may have choked on his own vomit and bruising was found on his body, police sources said.

The Medical Examiner’s officer will determine the cause of death.

No arrests have been made.