Police and medic units were called out to a home on the 5400 block of Eastwick Terrace in Southwest Philadelphia around 2:00 p.m. for a report of an unresponsive child.
A medic unit transported the child to Children's Hospital where he was pronounced dead at 2:18 p.m.
Investigators say the child was found with blood in his nose and on the bed.
A detective on the scene told Action News the death looks suspicious, in part because of that blood. Police also say the parents told them the boy did not feel well on Tuesday night, and did not go to school on Wednesday because everyone overslept.
Investigators also say the boy did not have any significant health issues.
However, detectives said the child could have died of natural causes, but won't know until an autopsy is completed on Thursday.
Neighbors didn't know much about the family, saying they had just moved in a few weeks ago.
The name of the boy has not been released.