Published: Oct 28, 2010 10:52 PM EDT
Updated: Oct 28, 2010 7:52 PM EDT

ARLINGTON, Fla. (AP) - Authorities in north Florida are investigating the death of a 4-day-old boy who died after being attacked by the family's pit bull.

Justin Daniel Valentin was mauled by the dog at his family's home near Jacksonville on Sunday. He was taken to Shands Jacksonville Medical Center, where he died the next day.

Florida Department of Children & Families spokesman John Harrell said the agency will try to determine whether there were any other incidents involving children and the dog.

He said they will also ask whether the child was unsupervised.

Harrell called the incident a tragedy and extended his sympathies to the family.