Police say a 5-year-old boy has been mauled to death Monday night by a dog on the South Side of Chicago.

Police say the attack happened in Gresham. The boy was taken to Advocate Christ Medical Center, where he was pronounced dead.

Neighbors told WLS-TV that people hit the dog with rocks and other objects, killing it and freeing the boy. They said the dog was a pit bull. Marquis Lewis says he didn't realize at first that the boy was being mauled.

"I hear someone yelling, 'He has my baby! Somebody please help me!' When I looked, I thought someone was fighting. When I looked closer, the dog had the child by the neck and shoulder," Bianca White, who lives nearby, told ABC 7 Chicago.

Police are investigating. No charges have been filed or tickets issued.

The Associated Press contributed to this report