Police say the cleaner, River Rosenquist, was supposed to be cleaning the public restrooms when he entered an unauthorized area of the zoo and attempted to feed or pet Eko, an 8-year-old Malayan tiger.
Rosenquist, who works for a third-party cleaning service, stuck his arm through the fence of Eko's enclosure and nearly lost his life and limb when Eko clamped down on it.
A police officer responding to the 911 call from a zoo employee arrived to a horrific sight. "Oh my god, is that real?" he asked a zoo employee.
The graphic video shows Rosenquist lying outside the fence, screaming in pain as Eko attempted to pull his mangled arm through the fence.
"Please help me! Please help me!" Rosenquist cried.
After kicking the fence, the officer asked if anyone had a tranquilizer gun to sedate the large animal.
Rosenquist screamed, "I'm gonna die! Shoot him! Shoot him! Shoot him!"
"You're gonna have to shoot it man," said a medic. The officer fired a single gunshot into Eko's head, as the wounded tiger grunted and fled into the darkness.
As medics tended to Rosenquist, a zoo veterinarian arrived and entered the enclosure to find Eko deceased.
Rosenquist was transported to a local hospital. His condition is unknown. It is not clear if he will face criminal charges.
"Our deputy did everything he could do in that situation and he ultimately made the only possible decision he could in order to save this man's life," Collier County Sheriff Kevin Rambosk said in a press release.
"This was a tragic encounter at our world-class zoo facility. We value our community partnership with the Naples Zoo and their focus on conservation and education."