MILFORD, Mass. - Massachusetts prison officials say former NFL star Aaron Hernandez has hanged himself in his cell and has been pronounced dead at a hospital. He was 27.

An official with the Massachusetts Department of Corrections says Hernandez was found hanged in his cell just after 3 a.m. Wednesday. Authorities tried to revive the former New England Patriots tight end, and he was pronounced dead at UMass Memorial - HealthAlliance Hospital in Leominster at 4:07 a.m.

Prison officials say the Hernandez was in a single cell in a general population housing unit at the Souza Baranowski Correctional Center in Shirley, Massachusetts They say he hanged himself using a bed sheet that he attached to a cell window.

Authorities say Hernandez tried to block the cell door from the inside by jamming the door with various items.

Hernandez, who was serving a life sentence for a 2013 murder, was acquitted Friday in a 2012 double slaying prosecutors said was fueled by his anger over a drink spilled at a nightclub.

The New England Patriots learned of former tight end Aaron Hernandez's apparent suicide as they prepared to go to the White House to celebrate their fifth Super Bowl title.

Patriots spokesman Stacey James said: "We are aware of the reports but I don't anticipate that we will be commenting today."

Hernandez played three seasons for the team before he was arrested and charged with murder in the 2013 shooting of Odin Lloyd, who was dating his fiancee's sister. Hernandez was acquitted just days ago of the 2012 shootings of two other men in Boston.

A look at key moments for former NFL star Aaron Hernandez:

- June 8, 2010: Hernandez, a standout tight end drafted from the University of Florida, signs a four-year contract with the New England Patriots.

- Jan. 1, 2012: He sets a career best with 138 receiving yards in a win over Buffalo.

- July 16, 2012: Two men, Daniel de Abreu and Safiro Furtado, are shot to death in their car as they wait at a red light in Boston's South End neighborhood.

- Aug. 27, 2012: Hernandez signs a five-year, $40 million contract with the Patriots.

- February 2013: An associate, Alexander Bradley, is shot in the face in Florida. Bradley files a lawsuit alleging that Hernandez shot him after they argued at a strip club.

- June 17, 2013: The body of Odin Lloyd, a semi-professional football player who was dating the sister of Hernandez's fiancee, is found about a mile from Hernandez's mansion in North Attleborough, Massachusetts.

- June 26, 2013: Hernandez is arrested on a murder charge in Lloyd's slaying and taken from his home in handcuffs. He later pleads not guilty. The Patriots release him hours after his arrest.

- May 15, 2014: Hernandez is indicted on two counts of first-degree murder and other charges in connection with the shootings of de Abreu and Furtado. His lawyers say he is innocent.

- May 28, 2014: Hernandez pleads not guilty to charges in connection with the deaths of de Abreu and Furtado. A prosecutor says Hernandez was angry because de Abreu accidentally bumped into him at a nightclub while dancing, spilling his drink.

- Jan. 9, 2015: Hernandez goes on trial for murder in Lloyd's killing.

- April 7, 2015: Prosecutors and Hernandez's lawyers present their closing statements and the case goes to the jury.

- April 15, 2015: Hernandez is convicted of first-degree murder; carries a mandatory sentence of life imprisonment.

- Feb. 14, 2017: Hernandez goes on trial for murder in the 2012 killings of Daniel de Abreu and Safiro Furtado.

- April 6, 2017: Prosecutors and Hernandez's lawyers present their closing arguments.

- April 7, 2017: The jury begins deliberating.

- April 14, 2017: Hernandez acquitted of murder in the 2012 killings of Daniel de Abreu and Safiro Furtado.

- April 19, 2017: Hernandez found hanging by a bed sheet in his prison cell, dies at hospital.