A theatre and a production company have been fined £28,000 after a stage collapsed during a musical.
Audiences are encouraged to dress as nuns and Julie Andrews
Thirty people were hurt during Sing-Along-A-Sound-of-Music at Birmingham's Alexandra Theatre.
Audience members, many dressed as nuns, had climbed onto the stage to join in a song before they fell 20ft into the orchestra pit in September 2003.
Producers Sing Along Productions and theatre managers Clear Channel were also ordered to pay £22,000 in costs.
The two companies, who admitted breaching health and safety laws in January, were sentenced at Birmingham Crown Court on Wednesday.
Judge William Everard said the accident was "wholly avoidable" and would not have happened had the compere, Debbie King, been warned that a temporary stage covering the orchestra pit was unsafe.
"It is plain that it was a terrifying incident for them and for their friends and families and for other people who saw what was happening," he said.
The victims are now suing for compensation
Members of the audience, who are encouraged to dress as nuns, members of the Von Trapp family and Julie Andrews, had been invited up for a "best-dressed nun contest" when the accident happened.
Eyewitnesses said people were standing on temporary boards covering the theatre's orchestra pit when it collapsed.
Injuries the theatre-goers sustained ranged from cuts and bruises to multiple fractures.
Outside the court, Ben Freedman from the production company apologised to the victims.
He said he wanted to re-iterate that the company was continuing to do "everything possible" to ensure that a similar situation never happened again.
The victims are now suing for compensation for their physical injuries and the psychological trauma of being involved in the incident.