TUCSON, Ariz. (AP) _ A toddler was mauled Tuesday by his family's Rottweiler, leaving him in serious condition at the hospital.

A deputy shot and killed the dog when he saw it attacking the boy, said sheriff's Sgt. Bradley Foust.

Twenty-one-month old Dillon Clark was airlifted to University Medical Center, where spokeswoman Judy Bernas said he was in serious condition but had stable vital signs.

Foust said the boy suffered severe injuries to his head and genital area. The attack occurred in the back yard of the home while the mother was inside, Foust said.

A neighbor saw the attack and called 911.