According to police, the dog was chained outside, broke his collar, and entered the residence where the attack took place. The child did not live at the residence but was visiting a friend at the time. When police arrived, the dog was actively attacking and only released his hold when tased. The dog was shot and killed when he tried to resume his attack.
Studies do not show pit bulls to be disproportionately dangerous; however, they can exhibit a bite-hold-shake behavior and refuse to release. And, with their strong jaws, pit bull bites are particularly serious because they bite deeply and grind their molars.