A one-year-old boy has died after a Rottweiler dog snatched him from the arms of another child at his grandparents' home in Wakefield.
The youngster was found with serious injuries by paramedics and police officers who found him in the back yard of the house where he was spending the Christmas holidays.
Police said the toddler was being carried by a seven-year-old child to the kitchen door, which leads to the back yard where his grandparents' pet dog was kept.
The seven-year-old intended to stroke the dog but after the door was opened, the dog snatched the one-year-old from the youngster and carried him into the yard.
Clearly distressed, the child then alerted his 16-year-old aunt, who was upstairs at the time.
The teenager attempted to recover the child but the dog would not let go of the child and she went back inside the house to call the emergency services, who arrived and took him to Pinderfields General Hospital.
Detective Superintendent Steve Payne, who is leading the investigation, said: "Clearly our thoughts go out to the family at this tragic time.
"The circumstances of the incident are still unfolding and we are speaking to the children that were present at the scene.
"What we know at this time is that the dog was a family pet, a two and a half year old female Rottweiller, which the family had owned for about six months.
"Although the dog lived in the yard of the premises, it had interacted with members of the family including children, and another dog and cat at the house, and had showed no previous signs of any aggression.
"Armed officers who the scene found the Rottweiller in an agitated state and clearly representing a potential danger to others, and a decision was made to destroy the animal."
Rottweiler attacks are rare but when they do happen the injuries are significant, Chris Window from the Rottweiler Club said.
"All breeds of dogs are animals. They do revert to animal instincts. If a dog is confronted with a situation they are not used to, they can react unexpectedly," he said.
He added: "If a dog is brought up in a household where there are no children you have got to be extra careful where children are present."