Updated at: 03/24/2014 11:57 AM
An injured woman is assisted by emergency services after incident at the Apollo Theatre in London.
(AP) LONDON - LONDON (AP) â€” Weakened, century-old cloth and plaster ties caused a partial ceiling collapse that injured almost 80 audience members at London's Apollo Theatre, investigators said Monday.
Westminster Council said the "principal cause" of the collapse was the deterioration of the hessian and plaster of Paris ties, used to bind the timber frames supporting the suspended ceiling. They had been in place since the Apollo Theatre opened in 1901.
Seven people were seriously hurt and scores more slightly injured when chunks of plaster and wood fell from the theater ceiling during a performance of "The Curious Incident of the Dog in the Night-time" on Dec. 19.
The venue is due to reopen Wednesday, with a new show, "Let the Right One In" â€” and a protective deck installed under the ceiling.
The council said it was sending advice to several dozen other London theaters and to English Heritage, which oversees hundreds of historic buildings. Many of London's theaters date from the same Edwardian era as the Apollo.
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