NEW YORK— A visitor to the Bronx Zoo was mauled by a tiger on Friday after he leaped from an elevated monorail train and plummeted over a fence into an exhibit, police and zoo officials said. The man lost his leg in the mauling.

The attack happened at around 3 p.m. in the Wild Asia exhibit, where a train with open sides takes visitors over the Bronx River and through a forest, where they glide along the top edge of a fence, past elephants, deer and a tiger enclosure.

Passengers aren’t strapped in on the ride, and the 25-year-old man apparently jumped out of his train car, with a leap powerful enough to clear the perimeter fence.

Details of what happened next were unclear, but police said the tiger attacked. The zoo’s staff used a fire extinguisher to chase the tiger off, and the man was instructed to roll under a electrified wire to get to safety, zoo director Jim Breheny said in a statement. Zookeepers then called the tiger into a holding area.

The man was conscious and talking after the mauling, Breheny said.

“If not for the quick response by our staff and their ability to perform well in emergency situations, the outcome would have been very different,” he said.

Police said the man was hospitalized in critical condition.

The Bronx Zoo, one of the largest in the U.S., sprawls over 265 acres (107 hectares) and contains hundreds of animals, many in habitats meant to resemble natural settings. Its exhibits include Tiger Mountain, Congo Gorilla Forest and World of Reptiles.