A neighbor says the boy lived at his grandparent's home along with several cousins.
"Really nice family. Just always real nice, they play outside all the time, always having a good time, real good kids and it's just really sad that this has happened," said Arthur Kouns, a neighbor.
Neighbors say there were two pit bulls that lived at the home and animal control took at least one dog away.
The Union City Police Department will release more information on Tuesday.