American former prisoner Alan Gross said remembering how his family survived the Holocaust helped him through five years of imprisonment in Cuba, where he was held on espionage charges, according to interview excerpts released on Friday.Gross, 66, spoke out in what CBS News said was his first interview since his release in December 2014 as part of a historic diplomatic thaw between the United States and the neighboring communist island nation.Gross, who was an American government contractor when he was jailed in Cuba, said he was threatened with death and torture, according to CBS, which plans to air the full interview on Sunday."They threatened to hang me. They threatened to pull out my fingernails. They said I'd never see the light of day," he told the television network. To get through the ordeal he focused on three things, he said: "I thought about my family that survived the Holocaust, I exercised religiously every day, and I found something every day to laugh at."While imprisoned, he would refuse to eat, lost 100 pounds (46 kg) and grieved for his mother's death form cancer. In his last few months he stopped taking visitors.