(CNN) -- Authorities in Alabama are investigating the death of a 5-year-old boy who was attacked in his yard by a pack of up to a dozen dogs.
An autopsy will be conducted Tuesday and charges are pending, said Heath Taylor, chief investigator and sheriff-elect for the Russell County Sheriff's Office.
The child was home with a babysitter in Phenix City, Alabama, Monday afternoon when he darted outside into the fenced yard and was attacked, Taylor said.
Animal control investigators determined 12 dogs were involved, but it was not clear how many of them bit the boy.
One of the dogs involved belonged to the boy's family, Taylor said. The 11 others belonged to neighbors and apparently slipped under the fence, he said.
"This is a horrible tragedy because both families know each other," he said.
Taylor said the dogs were from mixed breeds, and none of them were pit bulls.
"All 12 dogs are in custody and will be put down," he said.