Rizzuto, who returned to Canada in 2012 after spending six years in a U.S. prison, died of natural causes, said Maude Hebert-Chaput of Montreal's Sacre-Coeur Hospital.
Experts say his death signals the end of the Rizzuto clan's decades-old influence on organized crime because no successors sharing his family name are expected to emerge to replace him.
The death, meanwhile, of such a noted crime figure will leave a void in the international underworld, raising the possibility of violence as others manoeuvre for his former turf.
"Whenever they call (Rizzuto) the Canadian John Gotti or whatever, I just always laugh at it because John Gotti was a very big fish, but his pond was extremely small," said Lee Lamothe, who co-wrote the book, "The Sixth Family: The Collapse of the New York Mafia and the Rise of Vito Rizzuto."
Lamothe said the influence of Gotti, a notorious American crime boss, was mostly limited to New York, Florida and the U.S. Midwest.
"But Vito Rizzuto was a big fish in a big pond and he was the biggest fish — I'm talking globally," he said.
One example of Rizzuto's clout and confidence as a leader was apparent after he returned to Montreal in October 2012, following his prison term in Colorado.
While incarcerated, he lost many of the people closest to him as his empire came under attack amid the changing landscape in his absence.
His son and father were both murdered, his brother-in-law vanished, his father-in-law died of natural causes, and numerous friends were either imprisoned or died. Meanwhile, firebombings that targeted certain businesses had also taken place while he sat in prison.
"He came back, basically, to the O.K. Corral, where his family had been wiped out," said Julian Sher, an organized-crime expert, author and senior producer at CBC's The Fifth Estate.
"And then, in a period of about a year and a half, he reasserts power leaving behind quite a long trail of blood — huge Mafia wars and settling of accounts."
Sher said Rizzuto took back the reins of his organization over the past 14 months, thanks in large part to his huge network of connections and previously forged alliances.
"And yet he stuns everybody by coming out on top again and then he disappears quietly in the night," said Sher, who is expecting more blood to be spilled as others battle to fill the gap at the top that Rizzuto is leaving behind.
"We've seen a huge wave of violence since his return (from prison) ... There's no reason to think that that wave of violence won't continue now that he's gone. There's just going to be more of a power grab."
His rise to the top of a criminal organization was decades in the making.
At eight years old, Rizzuto arrived in Canada from Sicily in February 1954 and his family settled in Montreal. He grew up in the city's largely Italian districts of Villeray and St-Leonard, says Lamothe's book.
By the 1960s, the book says, his father, Nicolo, had become the boss of a Mafia organization in Montreal, creating an atmosphere that shaped the younger Rizzuto's future.
"Young Vito was immersed in outlaw culture from the day he was born and, as he grew, he assimilated the accepted and expected behaviour of his family," Lamothe wrote in the book, which was co-authored by Adrian Humphreys.
"Everywhere Vito looked, on both sides of the family, he encountered outlaw role models."
Lamothe said the history of organized crime in the Rizzuto family stretches at least as far back and his grandfather, Vito, who was killed in the United States in the 1930s.
Over the decades, Rizzuto's father laid the groundwork for a strong organization in Montreal, with the family becoming the leading Mafia family in Montreal by the 1980s.
Vito Rizzuto was viewed as a charismatic, natural leader who had an ability to maintain a delicate measure of peace with his Sicilian clan's rivals, including Calabrians in Ontario as well as Montreal's bikers and street gangs.
"The secret of the Rizzuto crime family's success was not violence, but was the ability to build a political and financial connection in Canada and in other parts of the world," said Antonio Nicaso, a Toronto-based author who has written extensively on the Mafia.
"Rizzuto was called the boss of both worlds, respected in Europe and very powerful in North America."
The family's lengthy hold on power, however, was eventually crippled following Rizzuto's extradition to the United States in 2006, two years after his arrest by Canadian authorities.
In 2007, Rizzuto was convicted on racketeering charges in a U.S. court for his role in the 1981 murder of three members of New York's notorious Bonanno crime family members. He was sentenced to 10 years in prison, minus time served while awaiting extradition.
The Rizzuto family also sustained a major blow in 2006 following Operation Colisee, a five-year police investigation that led to mass arrests in the largest sweep against the Italian Mafia in Canadian history.
By the time of his release last year from the Colorado prison, the ranks of Rizzuto's family and friends had thinned considerably.
Rizzuto's eldest son, Nicolo Jr., was killed in broad daylight in December 2009. That brazen shooting would set off a spate of slayings and disappearances targeting some of Rizzuto's closest allies and associates.
Paolo Renda, Rizzuto's brother-in-law and the consigliere of the clan, disappeared in May 2010, vanishing from near his luxury home in north-end Montreal. Family members found his car but no trace of Renda, who has not been heard from since.
A well-known Rizzuto ally, Agostino Cuntrera, 66, was gunned down in front of his food-distribution business in June 2010.
In November 2010, Rizzuto's father was shot and killed as he prepared to sit down to dinner with his wife and daughter. The elder Rizzuto, 86, was hit by a sniper's bullet through the window in his own mansion, near Vito's home.
A year later, a man police believe was making a play for the leadership of Rizzuto's old network met his own demise. Salvatore Montagna, a Canadian who was named by U.S. authorities as a former head of the Bonanno family, was gunned down near the banks of a river near Montreal.
Six people were arrested in connection with Montagna's slaying including Raynald Desjardins, a former Rizzuto confidant once described as his right-hand man.
Rizzuto's ability to apparently regain control of his organization after leaving jail came as a surprise to some experts.
As did Rizzuto's natural death, said Pierre de Champlain, a retired RCMP analyst.
"If Vito had been assassinated, I would have said, 'Ah, OK. That's the way of life,'" de Champlain said.
He says any person hoping to fill to the void left by Rizzuto's death will likely have to wield charismatic leadership qualities to unite criminal organizations and families in Montreal and Ontario.
"That's the big question," de Champlain said of what the future holds for the Mafia following Rizzuto's death.
"If the person who tries to lead the Mafia in Montreal cannot create consensus around him, then there will be a risk of violence."
Andre Cedilot, a Quebec journalist who co-wrote the book "Mafia Inc.," said he expects the underworld to experience a period of destabilization, but he doesn't know who will emerge to take over from the Rizzutos.
The amount of violence that ensues will likely be linked to how long it takes for the transition to run its course, he added.
"Organized crime can't remain leaderless," Cedilot said.
"Otherwise it will be chaos."
Rizzuto's reach — and his notoriety — stretched well beyond Canada, extending to South America and Europe.
Word of his death even made it onto the website of Italy's Corriere della Sera newspaper, where a headline Monday read: "The Mafia's last 'Don,' Vito Rizzuto, dead in Canada."
In 2005, Italian prosecutors filed charges against Rizzuto over allegations the Mafia was involved in the building of a multibillion-dollar bridge linking mainland Italy to Sicily.
That bridge was to be one of that country's largest-ever public works projects — a dream of myriad people in that region that had gone unfulfilled since the early days of the Roman Empire.
At home, hints of the scope of Rizzuto's influence have emerged in testimony at Quebec's corruption inquiry.
Last year, the Charbonneau Commission heard how he once helped decide who built the roads in Quebec.
A construction boss testified that amid a dispute over who should win a certain bid for a road project, he was invited to a restaurant owned by his competitor.
Sitting there, acting as mediator, was Rizzuto himself.
"I was a bit very surprised (to see Rizzuto there)," Lino Zambito said in his October 2012 testimony.
Rizzuto, acting as an impartial observer, apparently suggested to Zambito that perhaps his young company didn't have the expertise required to pull off a job as big as renovating Montreal's Acadie Circle.
That was enough for Zambito, who did not bid on the contract.
Lamothe said Rizzuto was relatively easygoing in the sense that he didn't have to go around beating people up because he knew how a negotiation would end. He also said everyone around Rizzuto made money, which gave him even more power in the underworld.
"He was a winner," Lamothe said. "It's a horrible thing to say about a gangster, but he was perfect in his world."
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