Controversial labor leader Jimmy Hoffa disappeared in the summer of 1975, and despite great public and official interest, there is no substantial or reliable trace of his whereabouts or ultimate fate. There are a number of theories on the subject, ranging from the fantastic, such as the idea that Hoffa's body is encased within concrete at New Jersey's Giants Stadium, to the mundane, such as the theory that Hoffa was murdered and then dumped in a swampy area of Florida.
Professional and civilian investigators have worked for years to find a solution to the mystery of Hoffa's disappearance, and though he was declared dead in 1983, no trace of human remains that can be confirmed as belonging to Hoffa have ever been found, and the case of his disappearance remains open as of 2015.
Hoffa was a controversial figure in his time, and in addition to being in trouble with legal authorities, Hoffa had some conflicts with organized crime. Perhaps because he had so many enemies, it has been difficult for authorities to narrow down the myriad options that could explain his disappearance. Most of the theories of Hoffa's whereabouts are the subject of urban legend. Many of these myths purport that Hoffa's body is encased in or buried underneath something, such as a swimming pool in a backyard in Michigan, or that his remains were obliterated by processes such as fat rendering.