MICHAEL JACKSON's 12-year-old son watched him collapse in disbelief, convinced his dad was "clowning around" - according to a family friend.
Jackson biographer Stacy Brown claims 'Prince' Michael Jackson Jr was in the living room of their rented California home with his dad when the singer fell to the ground.
Brown insists Prince then watched in silence while his dad's doctor Conrad Murray fought frantically to save his life.
The author tells the New York Post, "The horror of it all is that Prince thought this dad was just being his dad and clowning, but it was real and he watched as they worked on him.
"Prince was stunned - in a trance - just watching."
Meanwhile Michael's manager and longtime friend Frank DiLeo revealed how he told the kids of their father's death.
He said Paris screamed: "No, no, Daddy. No!" then fell sobbing into her granmother Katehrine's arms, while Prince Jnr wailed in agony.
Mr DiLeo said: It was the single most painful moment of my life."
Michael's father Joe, 79, said in a statement the family is "speechless" over the star's loss.
He added: "My grandchildren are deeply moved by all the love and support you have shown for them."
Jackson was declared dead onThursday, June 25th, at Los Angeles's UCLA Medical Center.