THE BRONX — A man was mauled by a 400-pound tiger after leaping into its den at the Bronx Zoo Friday afternoon in an apparent suicide attempt, officials and sources said.

The man was riding the zoo's monorail, which passes over the den, when he jumped out of his seat as the train passed the tiger exhibit at 3 p.m., zoo officials said. The monorail has an open-air front area, with a series of metal guardrails.

As horrified zoo patrons looked on, the man, identified by sources as 25-year-old David Villalobos, fell 17 feet and landed on the ground inside the den, where he was mauled by a tiger, sources said.

Villalobos, who officials said visited the zoo alone, told those who rescued him that he jumped in on purpose because "he wanted to die," sources said.

Villalobos' right foot and left leg were clawed, and he was bitten on the back, where a fang punctured his lung, sources said. Zoo officials said he also suffered bites on his arms and shoulder.

Villalobos was bleeding "badly" when he was removed from the cage, the FDNY said. He was taken to Jacobi Medical Center, where he was in critical but stable condition Friday evening, police said.

Bronx Zoo personnel rescued Villalobos after racing to the den and distracting the tiger using a fire extinguisher, zoo personnel said in a statement.

"A passenger on the Bronx Zoo’s Wild Asia Monorail jumped out of the car he was riding in, clearing the exhibit’s perimeter fence into a tiger exhibit," the zoo said. "Our emergency response staff immediately went to the site and used a CO2 fire extinguisher to move the tiger away from the person.

"Once the tiger backed off, the man was instructed to roll under a hot wire to safety," the zoo's statement continued. "The keepers were able to call the tiger into its off exhibit holding area and safely secured the animal. The man, about 25 years of age, conscious and talking, was taken to the hospital by ambulance. 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."

The tiger who attacked Villalobos was 11-year-old Bachuta, a 400-pound male Amur, also known as a Siberian tiger, said Jim Breheny, the zoo's director. Bachuta was the only tiger in the exhibit at the time of the attack.

In a press conference at the zoo Friday evening, Breheny said the zoo had been prepared to use deadly force to restrain the tiger — though, he added, "The tiger did nothing wrong in this episode."

Breheny also defended the safety of the monorail, which he said had been open for 35 years.

"When someone is determined to do something harmful to themselves, it's very hard to stop them," Breheny said.

"Anytime something like this happens, obviously we review everything," Breheny continued, "but we honestly think we provide a safe experience and this is just an extraordinary thing that happened."

With reporting by Victoria Bekiempis and Jessica Campbell.