Five hundred theatregoers arriving for the first night of a hit musical had to be offered their money back after a backstage crisis at Chichester Festival Theatre.

Singer Susannah Fellows was struck down with laryngitis and Clare Burt, who features in one of the big dance routines in the show Pal Joey, hurt her ankle during rehearsals.

It is thought to be the first time the theatre has cancelled a performance after what spokeswoman Vicky Edwards called a "totally freak occurrence."

She said: "I have been involved with this business for 25 years and I have never known anything like this to happen.

"Susannah just could not sing and at 7.30pm, when the show was due to start, Clare was still in the hospital casualty department."

Theatre director Andrew Welch broke the news to people as they arrived for the show offering refunds or tickets for another performance.

The revival of Pal Joey, which has been nominated for a top theatrical award, won rave reviews earlier this year at Chichester's smaller Minerva Studio Theatre.

One theatregoer said: "I think people were disappointed but they were all very understanding about the situation. It was a great shame that it should happen on the musical's first night in the main theatre."

The second night of the show went ahead last night after Susannah had spent 24 hours resting her voice and Clare's dance routine was altered.