James “Whitey” Bulger, the former South Boston mob boss and longtime FBI informant, was killed while serving a life sentence inside a federal prison.

An official from the Bureau of Prisons says at approximately 8:20 AM Bulger was found unresponsive, adding “Life-saving measures were initiated immediately by responding staff.” He was later pronounced dead by the local medical examiner.

In 2013, a federal jury convicted him of participating in 11 murders throughout the ’70s and ’80s. He was captured two years earlier hiding out in an apartment in Santa Monica, CA after being on the run for more than 16 years.

89-year-old Bulger, was just transferred to the high-security USP Hazelton in West Virginia.

Bulger became infamous in pop-culture after Jack Nicholson played a character loosely based on his life in Martin Scorsese‘s “The Departed.” He was also portrayed by Johnny Depp in “Black Mass.”