Officials say an investigation has been launched to determine how she managed to enter the enclosure through an unlocked door. Shouri had spent 12 of her 13 years at the park. The park, located 100 miles (160 kilometers) west of London, was not open to the public at the time.
Shouri's death came four days after a Sumatran tiger was killed by a prospective mate at London Zoo. Amur tigers are an endangered species with as few as 500 left in the wild.