DETROIT (AP) -- It was September 2012 and dozens of residents looked on as police cordoned off the area around a shed just northeast of Detroit.

Low whispers about what -- or who -- officers were searching for grew to more excited chatter when the name Jimmy Hoffa started floating around the normally quiet street.

By that time, the name had become sort of mythical in and around Detroit.

Wednesday marks 50 years since the iron-fisted former Teamsters union boss disappeared from a restaurant about 10 miles (16 kilometers) north of the city. Presumed dead long before being legally declared deceased in 1982, Hoffa's remains were not found beneath the concrete shed floor in Roseville in 2012.

Nor were they uncovered eight years earlier, below floorboards in a Detroit house. Neither were they found in 2013 at a horse farm miles northwest of the city.

In 2013, digging equipment found mostly dirt as authorities excavated a field in Oakland Township, about 25 miles (40 kilometers) north of Detroit. And no signs of Hoffa were found in 2022 during a search of land beneath the Pulaski Skyway in New Jersey.

Hoffa, the son of a coal miner who died when he was 7, was born in Brazil, Indiana, but moved with his mother to Detroit while still a boy. He quit school at 14 and went to work, landing a job on a grocery warehouse loading dock.

In 1932, Hoffa led a workers' strike over poor labor conditions and unfair treatment of workers by the store, according to a post about him on the International Brotherhood of Teamsters website.

He joined the union a year later and became a business agent for Local 299 in Detroit, the website said.

Hoffa was elected the local's president in 1937 and would become a union organizer. He often found himself on the other end of the law. In 1937, he was convicted of assault and battery. In 1940, he pleaded no contest to charges of conspiring with unionized waste-paper companies to prevent non-union competitors from selling their products. Seven years later, he was arrested for attempted extortion. Each time, Hoffa only received fines.

He continued to rise in the union's ranks. From 1957 to 1971, he served as the Teamsters general president.

Hoffa had a history of associating with organized crime. In the late 1960s, he was convicted of fraud, conspiracy and jury tampering. He was sent to federal prison in 1967. President Richard Nixon commuted Hoffa's 13-year sentence in 1971.

On July 30, 1975, Hoffa, now 62, was to meet reputed Detroit mob enforcer Anthony "Tony Jack" Giacalone and alleged New Jersey mob figure Anthony "Tony Pro" Provenzano at the Machus Red Fox restaurant in Oakland County's Bloomfield Township.

Hoffa called his wife, Josephine, about 2:15 p.m. from a pay phone to tell her no one showed up for the meeting. He has not been seen or heard from since despite scores of tips and multiple searches spanning several states.

A grand jury later was convened in Detroit, but no one ever has been directly charged in Hoffa's disappearance or death.

"I think it confirms in my mind ... somebody did a pretty good hit job on him," Wayne State University educator Marick Masters said of Hoffa.

Masters, professor emeritus at the university's Mike Ilitch School of Business in Detroit, told The Associated Press on Wednesday that Hoffa was considering getting back into Teamsters' leadership at the time of his disappearance.

"He still, obviously, was very much passionately involved in the union and he wanted to find a way of moving forward in it," Masters said. "Whatever the circumstances were, he was tragically prevented from doing that."

Hoffa was inducted into Labor's International Hall of Fame in 1999, according to the International Brotherhood of Teamsters, which refers to Hoffa on its website as "a worker's hero."

"He was viewed as a very passionate champion of the Teamsters," Masters said. "On the other hand, he had problematic associations which besmirched the image of organized labor. He was a very controversial figure. He was capable of accomplishing things and also capable of having associations that raised questions about his integrity."