James “Whitey’’ Bulger, the ruthless Boston gangster who eluded authorities for 16 years before being captured and then convicted in 2013 of participating in 11 murders, has died at a prison in West Virginia.

Bulger, 89, was found dead Tuesday, the Federal Bureau of Prisons confirmed. It said Bulger had arrived at the Hazelton Penitentiary in Bruceton Mills, West Virginia, on Monday.

Authorities did not immediately release a cause of death, but Justin Tarovisky, a prison union official, told The Associated Press the death was being investigated as a homicide. The FBI has opened an inquiry.

Another prison union official who was not authorized to comment publicly said Bulger was beaten to death and wrapped in blankets to appear as if he were sleeping. Video surveillance showed at least two inmates going in and later exiting the cell before the body was discovered by two officers.

The officers initially checked Bulger’s cell because he had not appeared for breakfast, the official said. When covers were removed from the unresponsive Bulger, officers reported he appeared bloodied and severely beaten.

The official said Bulger was abruptly moved from a federal prison complex in Florida after allegedly threatening a health service staffer. He was placed in a solitary confinement cell there, then routed through a facility in Oklahoma City before his transfer to Hazelton.

More:A look at the 19 murder victims in Whitey Bulger’s trial

Bulger, who was serving a life sentence, had been in poor health for some time.

Known as one of the nation's most notorious criminals and fugitives, Bulger – nicknamed “Whitey” for his bright platinum hair – was the head of a violent South Boston crime ring known as the Winter Hill Gang from the 1970s into the 1990s.

In December 1994, Bulger was tipped off about his imminent indictment by an FBI agent and escaped. He remained on the FBI’s 10 Most Wanted list until he was apprehended in 2011 in Santa Monica, California.

His life of crime inspired several movies, including "Black Mass'' and “The Departed,’’ which won an Oscar for best picture of 2006.

Adding intrigue to his story was the FBI's contention that Bulger was a longtime informant – which he denied – and the fact his younger brother, William "Billy'' Bulger, became one of Massachusetts' most powerful politicians as president of the state Senate for 18 years.

Bulger was seen as a Robin Hood by some: helping old ladies across the street and giving turkey dinners to neighbors at Thanksgiving. But authorities said he was diabolical and would kill anyone who would cross him.

Among the slayings linked to Bulger was the shooting death of Oklahoma entrepreneur Roger Wheeler, who was gunned down outside his country club in Tulsa in 1981. Bulger was also convicted for his role in murders in several states and for racketeering, extortion, drug dealing, money laundering and weapons possession.

Patricia Donahue’s husband, Michael, was killed in 1982 when he offered a ride home to a man allegedly targeted for death by Bulger because he was talking to the FBI. “I’d like to open up a champagne bottle and celebrate,” Donahue told WBZ-TV in Boston on Tuesday.

Tom Duffy, a retired state police detective who hunted Bulger and was a consultant on "The Departed," called word of the gangster's death “celebratory news.”

Contributing: The Associated Press