Liza Minnelli collapsed on stage during a performance in Sweden and was rushed back to the United States for medical treatment, a concert spokesman said Thursday.

The sixty-one year old singer was performing in a Christmas show Wednesday in Goteborg, Sweden’s second biggest city, but collapsed as she walked off stage after finishing her fourth act, Zlakto Nedanovski, a spokesman for the concert organizers said.

“As she walked down the steps, she passed out. She was taken immediately to her hotel where a doctor was waiting,” Nedanovski told The Associated Press.

He said Minnelli was flown to the United States on Thursday on the advice of her doctors there.

“They decided together with her management that it’s best for Liza to go to the U.S. right away,” Nedanovski said, adding he did not know what her medical diagnosis was.

“She had felt a bit dizzy before she got up on stage,” but decided to proceed with the show anyway,” Nedanovski said.