Former New England Patriot Aaron Hernandez has died in a Massachusetts jail.

According to the Massachusetts Department of Corrections, Hernandez was discovered hanged in his cell around 3:05 a.m. Hernandez was pronounced dead at 4:07 a.m. at UMASS Leominster after efforts to save him failed.

“Mr. Hernandez was in a single cell in a general population unit,” the statement said. “Mr. Hernandez hanged himself utilizing a bedsheet that he attached to his cell window. Mr. Hernandez also attempted to block his door from the inside by jamming the door with various items.”

State Police are investigating, and his family has been notified.

Hernandez was serving a life sentence for the 2013 murder of Odin Lloyd.