Well, he didn't "lose" it, really. A tiger took it, with its mouth.
Police say it appears the 25-year-old man intentionally jumped into the Bronx Zoo tiger den; DNA Info says he leapt from his seat on the zoo's monorail, which passes overhead of it.
The man reportedly told his rescuers he jumped because "he wanted to die."
Police confirm he remains in critical condition in the hospital.
Image via Getty