Notorious Boston gangster James “Whitey” Bulger was killed Tuesday inside a federal prison in West Virginia — and investigators are probing whether he was beaten to death by another inmate or inmates, according to multiple senior law enforcement officials.

Bulger, 89, was found unresponsive about 8:20 a.m. at the high-security penitentiary USP Hazelton in West Virginia, according to a Justice Department statement.

“Life-saving measures were initiated immediately by responding staff,” the statement said.

But Bulger was subsequently pronounced dead by the Preston County Medical Examiner, the Justice Department said.

Bulger had arrived at the prison on Monday after being transferred from a Florida correctional facility.

(more at nbcnews.com)