Greene was hired by the Cleveland Solid Waste Trade Guild to "keep the peace". Impressed with his abilities, mobster
Alex "Shondor" Birns hired him as an enforcer for his various "
numbers" operators. The Cleveland Mafia family
underboss, Frank "Little Frank" Brancato, used Greene and other Irish-American gangsters, during the 1960s, to act as muscle to enforce the Mafia's influence over the garbage-hauling contracts and other rackets. Until his death in 1973, Brancato reportedly regretted having brought Greene into the mob due to the damage Greene did. For example, in May 1968, under Birns's orders, Greene was supposed to attack a black numbers man who was holding out on protection money due. Unfamiliar with the military-type detonator, Greene barely made it out of his car before the bomb exploded. He survived being thrown nearly 20 feet, although the hearing in his right ear was damaged for life. "Big Mike" Frato broke away from the Cleveland Solid Waste Trade Guild and founded the more legitimate trade group called the
Cuyahoga County Refuse Haulers Association. A legitimate businessman, he protested Greene's bringing mob involvement and strong-arm tactics to the guild (although he had his own connections). The Cleveland Solid Waste Trade Guild fell apart shortly thereafter. In September 1970, Greene instructed Art Sneperger to place a bomb on Frato's car, but Sneperger had second thoughts and told Frato. Sneperger was a police informant and told Sgt. Edward Kovacic of the
Cleveland Police intelligence unit about Greene's plans and Greene's role as an FBI informant. Greene once again ordered Sneperger to plant a
bomb on Frato's car in 1971. The bomb detonated before Sneperger could get away, killing him and sparing Frato, who was across the street. Police suspected that Greene may have purposefully detonated the bomb early with the intention of sending a message to Frato. Some investigators believed the premature explosion was caused by a radio signal, possibly from a shortwave radio or a passing police car. Others thought that Birns and Greene killed Sneperger after learning he was an informant. Sgt. Kovacic was told by an underworld source that Greene had pushed the detonator, killing Sneperger instantly. The case was never officially solved. On November 26, 1971, Frato was shot and killed at Cleveland's White City Beach. Greene was arrested and interrogated, he admitted to the killing but claimed self-defense. He said Frato had fired three shots at Greene, who was jogging and exercising his dogs and fired one back. Evidence seemed to corroborate Greene's story, and he was released. Cleveland police later learned Frato was armed and had an opportunity to kill Greene several weeks prior to the White Beach shooting. During their partnership, Greene and Frato had become so close that they had named sons after each other. Not long afterwards, Greene again found himself a target while jogging in White City Beach. A sniper, concealed several hundred feet away, fired several shots at Greene from a rifle. Instead of ducking to the ground, Greene pulled out his revolver and started shooting, while running toward his would-be assassin. The sniper fled and was never positively identified. Investigators learned that this attempt was part of a murder contract left by Birns. Greene left his wife and their three children for their own safety and moved to
Collinwood, where he rented an apartment. Journalist Ned Whelan wrote about Greene: "Imagining himself as a feudal baron, he supported a number of destitute Collinwood families, paid tuition to Catholic schools for various children and, like the gangsters of the Twenties, actually had 50 twenty-pound turkeys delivered to needy households on Thanksgiving." He often picked up restaurant tabs for friends, neighbors, and acquaintances, and left generous tips. Greene evicted a
bookmaker who operated out of a small Waterloo business, and kept a local bar in order by making personal visits.
The Celtic Club Greene formed his own crew of young
Irish-American gangsters, called "The Celtic Club". His main enforcers were Keith "The Enforcer" Ritson, Kevin McTaggart, Brian O'Donnell, Danny Greene Jr., Billy McDuffy, Elmer Brittain, Ernest "Ted" Waite, Art "Snep" Sneperger and Jimmy "Icepick" Sterling who set up gambling dens across the city. He also allied with
John Nardi, a
Cleveland crime family labor racketeer who wanted to overthrow the leadership. The relationship between Greene and Birns began to sour. Greene had asked Birns for a loan of $75,000 to set up a "cheat spot" (speakeasy and gambling house). Birns arranged for it through the
Gambino crime family, but the money was lost in the hands of Birns's courier Billy Cox, who used it to purchase
cocaine. The police raided Cox's house, arrested him, and seized the narcotics and what was left of the $75,000. The Gambino family wanted their money, and Birns pressed Greene, who refused to return it, reminding Birns that he could not return something he had never received and that Birns was responsible for it, since Birns's courier had lost it. To settle the dispute, Birns directed an associate to hire a hitman for Greene, gave him $25,000 for the job, and noted it should be carried out even in the event of any harm befalling Birns. Several minor underworld characters, burglars by trade, took the contract, but their numerous assassination attempts on Greene failed. Not long afterward, Greene found an unexploded bomb in his car when he pulled into a Collinwood service station to get gas. The explosive was wired improperly and failed to detonate. Greene disassembled the bomb himself, removed the dynamite, and brought the rest of the package to a policeman, Edward Kovacic. Kovacic offered him police protection, but Greene refused it. Suspecting that Birns had ordered the hit, Greene decided to retaliate. On March 29, 1975, Holy Saturday, the eve of Easter, Birns was blown up by a bomb containing
C-4, a potent military explosive, in the lot behind Christy's Lounge, formerly Jack & Jill West Lounge, a go-go spot at 2516 Detroit Ave. near St. Malachi's Church. On May 12, another explosion rocked Collinwood. Greene's building at 15805 Waterloo Road was destroyed, but he sustained only minor injuries. As the second floor fell, he was shielded from the debris by a refrigerator that had lodged against a wall. A second, more powerful bomb failed to explode, for which Greene credited the
intercession of
St. Jude, whose medal he always wore around his neck. In 1975, Greene began to push into the
vending machine racket, traditionally controlled by the Mafia, as well as muscling into gambling operations. This angered the Cleveland family leadership, especially the soldier
Thomas "The Chinaman" Sinito. Greene controlled some of the more lucrative laundry contracts that Sinito wanted, and Sinito deemed the fees excessive that Greene charged for coin-operated laundry contracts extortion. In Greene's competition with the Mafia to build a vending machine empire, John Conte became a victim. Conte owned a vending machine company (that provided slot machines to various private clubs and parties) while working as a route man for another one. Conte was also a close friend of
Joseph Gallo. On the day of Conte's disappearance, he told his wife he had a meeting with Greene. That was the last time she saw him; his badly beaten corpse was discovered a few days later at a dump site in
Austintown. Police investigators thought that Conte was beaten to death in Greene's trailer and his body later transported to Austintown. They found some physical evidence, but Greene was never charged with Conte's murder. In 1976, longtime mobster
John Scalish died, leaving control of Cleveland's lucrative criminal operations, specifically the city's Teamsters Union locals, up for grabs. Upon Scalish's death, Greene became the most powerful enemy of the Cleveland mob. Scalish had appointed
James Licavoli as his successor, but other mobsters, such as
John Nardi, challenged Licavoli for leadership of the organization. Within weeks, with Greene's assistance, Nardi had many of Licavoli's supporters killed, including Licavoli's underboss, Leo "Lips" Moceri. The Cleveland family's enforcer, Eugene "The Animal" Ciasullo, was seriously injured and sidelined for several months by a car bomb. Soon afterward, a bomb planted in Alfred "Allie" Calabrese's car killed an innocent man: Frank Pircio, of Collinwood, died while moving Calabrese's Lincoln Continental before getting his own car out of their shared driveway. This began a longstanding war between Licavoli's Cleveland crime family and Greene's Celtic Club. In 1976 alone, 36 bombs exploded around the Cleveland area, which was soon given the moniker "Bomb City, U.S.A." The
ATF tripled its staff in northeast Ohio in order to handle the bomb investigations. A suspected bombmaker, Martin Heidtman, was arrested but was released for lack of evidence. Rick Porrello reported in his book,
To Kill The Irishman, that Greene, using bombs or bullets, killed at least eight of the Mafia hitmen sent to assassinate him. ==Final days==