09/03/2012 AT 06:10 PM EDT
Michael Clarke Duncan, the Oscar-nominated star of The Green Mile
, died Monday in a Los Angeles hospital after two months of treatment for a heart attack
. He was 54.
The imposing 6-ft., 5-in., 300-lb. actor with a warm smile and gentle demeanor "never fully recovered" from the July 13 heart attack, according to a statement issued on behalf of his fiancée, the Rev. Omarosa Manigault, the former star of The Apprentice
"Manigault is grateful for all of your prayers and asks for privacy at this time," says the statement. "Celebrations of his life, both private and public, will be announced at a later date."
The Chicago-raised Duncan worked as a ditch digger for the gas company before coming to Los Angeles where he was a bodyguard for stars including Jamie Foxx and Will Smith
Duncan's breakout performance as imprisoned convicted murderer John Coffey in the 1999 Tom Hanks hit The Green Mile
earned him a supporting-actor Academy Award nomination.
He also appeared in such films as Armageddon
, Planet of the Apes
and The Whole Nine Yards
and provided his voice for Kung Fu Panda
"I am terribly saddened at the loss of Big Mike," Hanks said Monday. "He was the treasure we all discovered on the set of The Green Mile
. He was magic. He was a big love of man and his passing leaves us stunned."
Reporting by OLIVER JONES