"Halfway into Friday night's performance, Horn appeared alone on stage with the tiger and told the crowd the animal was making its debut in the show - a claim hotel officials said was part of the act.
The tiger, which weighs about 270 kilograms, then lunged at Horn, who tried to beat the animal off with a microphone.
"I knew he was in trouble right away. I was horrified," said Diane Weightman, who was in the audience. "I wanted to jump on stage and help him. I didn't know what to do."
Andy Cushman, also in the audience, said Horn "looked like a rag doll" as the tiger dragged him off the stage.
Feldman said stage crew members used fire extinguishers to distract the animal and free Roy.
After the attack, Fischbacher appeared on stage and told the 1,500 audience members the performance was cancelled, Cushman said.
Hotel officials said the show has been cancelled indefinitely. The tiger involved in the attack, a seven-year-old male named Montecore, was quarantined at the hotel, officials said.
Horn, who turned 59 on Friday, had never been injured during a show before. "Not a scratch, not by an animal," said Bernie Yuman, the duo's longtime manager. "
Just brutal, I couldn't imagine seeing that...