The 61-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 song, said Zlakto Nedanovski, a spokesman for the concert’s organizers.

“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.

Minnelli’s spokeswoman Liz Rosenberg confirmed in a statement that the artist “had complained of dizziness” before the show and “became very ill after the show began.”

“As a result, she was unable to finish her performance and was rushed back to her hotel by her manager,” Rosenberg said.

She said a doctor examined Minnelli “and in consultation with her New York physician, determined that it would be necessary for the Oscar winning actress and singer to immediately return to New York City to receive further medical evaluation.”

In a separate statement, released by concert organizer Svensk Nojesutveckling, Minnelli’s manager Gary Labriola said: “We don’t yet know what happened; we are all very worried.”

Minnelli was performing alongside several Swedish artists in a show called “A Classic Christmas Night.” It was the fourth and final show in a series of four concerts in Sweden, Rosenberg said.

Minnelli won an Oscar and a Golden Globe for her portrayal of Sally Bowles in the 1972 film “Cabaret.” She won an Emmy for the 1972 TV special “Liza with a Z.” She also won Tony Awards in 1974 and 1978. –