A man jumped into the tiger den at the Bronx Zoo this afternoon. According to FDNY, the incident happened before 4 p.m.; initial reports stated that an emotionally disturbed person jumped into the tiger exhibit (though a conflicting report says it was a lion den). "Someone jumped the gate at the bronx zoo n got maulled by a tiger now in jacobi ER.#lmfao," tweeted one witness.

Another person tweeted, "What idiot jumps in the tiger cage at the Bronx Zoo?" Three Amur tiger cubs made their debut at Tiger Mountain earlier this month. We'll update as we learn more information.

In 1987, an 11-year-old boy was fatally mauled by two polar bears in the Prospect Park Zoo. The boy had sneaked over a fence at night (the NY Times says he and friends were planning on wading there), and police officers shot and killed the bears.

Update: FDNY added that the victim was a man in his 20s, and he "reportedly jumped or fell into the tiger den" around 3:30 p.m. The victim is in "serious condition" at Jacobi Hospital now.

Update: Sources tell NBC that the victim lost his foot in the attack; other reports say the victim had a "severed leg."

Update: Sources tell DNAInfo that the victim was riding the monorail when he jumped out of his seat into into the tiger den. They add that the man's right foot and left leg were clawed, and his back was bitten, where a fang punctured his lung.

Below, you can see a video of the monorail (not the incident)—you can see a tiger at the :12 mark:

Update: Bronx Zoo Director Jim Breheny gave this statement about the incident:

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 around 3pm today. 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 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.