His girlfriend, reality TV personality Omarosa Stallworth, administered CPR while waiting for paramedics to arrive.
The former "Apprentice" star was able to revive her beau, who was then transported to an undisclosed hospital where his heart rate was stabilized in the Intensive Care Unit, the celebrity news Web site said. Tests are being conducted to see why his heart stopped.
Duncan, 54, has starred in the films "Armageddon," "The Green Mile," "The Whole Nine Yards," "Brother Bear" and "Daredevil."
Celebrity Couples of 2014 [PHOTOS]