London (CNN) -- The hundreds of theatergoers who packed into Central London's historic Apollo Theatre on Thursday night were expecting to watch a mystery.
But about 40 minutes into the play, shortly after 8 p.m., they got a drama instead.
"One of the actors said, 'Watch out!'" said one woman. "We thought it was part of the play."
It wasn't. Instead, it was part of the century-old structure's ornate plaster ceiling, which tumbled five stories onto the theatergoers, injuring scores of them, seven seriously, officials said.