A female zookeeper has died after being mauled by a jaguar at Denver Zoo in the United States, officials have said.The zookeeper, who was not named, was attacked inside the jaguar's enclosure on Saturday morning, prompting armed employees to rush to her aid.They shot and killed the animal after it threatened them, and the zoo was closed after the incident.The jaguar, a six-year-old male named Jorge weighing 140lbs (64kg), came to Denver Zoo from Bolivia in 2005."We are deeply saddened by this loss. It is with utmost sympathy that our condolences go out to this zookeeper's family and loved ones," Denver Zoo president Clayton Freiheit said in a statement on the zoo's website.