Olivia Newton-John has called off her concert Friday at Treasure Island Casino in Red Wing because of a back problem, the casino announced on Wednesday.
The veteran Aussie pop star, known for the hits "Let's Get Physical" and "I Honestly Love You" and for her roles in the films "Grease" and "Xanadu," has not yet rescheduled the Treasure Island concert. The casino said refunds will be given if requested by May 20. Otherwise, tickets will not be refunded and they will be honored for a rescheduled show.
Since late March, Newton-John, 68, has canceled several U.S. concert performances due to bronchitis.