A 23-year-old zookeeper in Mexico died of a heart attack Monday after he was attacked by a tiger while petting the animal, Metro reports. 

José de Jesús stood next to the chain-link fence enclosure and called over the Bengal tiger for feeding time. De Jesús extended his right hand through the gate to pet the tiger who initially appeared to accept the gesture. Then, all of a sudden, the tiger sunk its teeth into his hand. The man started screaming in agony as the tiger used its claws and clenched jaw to pull him closer.