The mother of a two-year-old boy who was mauled to death after falling into a zoo exhibit of wild African dogs will not be prosecuted.
Allegheny County District Attorney Stephen A Zappala Jr said Maddox Derkosh's death at the Pittsburgh Zoo was a "tragic accident".
The boy's mother, 34-year-old Elizabeth Derkosh, had put him on top of a railing to view a pack of African painted dogs in early November.
The boy fell off, the animals immediately pounced on him and he bled to death.
Mr Zappala said witnesses described the boy lunging forward, as if he thought there was some sort of clear barrier to stop him.
The district attorney said he is still investigating whether any charges will be filed against the zoo, and what changes need to be made there.