When zookeeper Sarah McClay was mauled to death by a Sumatran tiger at an animal park in England last week, its owner suggested she had violated safety procedures and entered the animal's pen. But on Monday, police said that's not what happened. Cumbria police said that, according to witnesses, the tiger escaped from its pen and attacked 24-year-old McClay on Friday as she was working in a staff area at South Lakes Wild Animal Park in northwestern England. She later died of her injuries in hospital. "What has become apparent from our inquiries with witnesses is that Sarah was going about her routine duties and was in the staff section of the enclosure building, which animals are not allowed access to, when a tiger … entered it from an adjacent pen and confronted her," Detective Chief Inspector Bob Qazi said in a statement. The tiger then attacked McClay, taking her from the building to an outside enclosure, where she was found by paramedics, Qazi added. Police said detectives do not suspect foul play or suicide and are still trying to find out how the tiger escaped. They said it could be because of a "human or system error, or mechanical failing, or a combination of both". Earlier, park owner David Gill told BBC radio he believed McClay had failed to follow safety rules and entered the tiger's pen for "an inexplicable reason".