A lot of folk suffered minor injuries after the incident which came about on Wednesday evening for the length of a efficiency of Demise Of A Salesman in London.
The force said the casualties suffered minor injuries.
Pictures shared online showed a large hole in the ceiling with wires hanging down.
"Thank you @WendellPierce for coming out to check everyone safe".
"We are so sorry that unfortunately, this happened".
He said there was water dripping before the collapse. He said that afterward "everyone got up and streamed down the stairs".
It is not yet known whether the Piccadilly Theatre has a suspended fibrous plaster ceiling, and no details about the cause of the collapse have yet been confirmed.
Describing the scene interior, journalist Martin George, 41, who became once sitting within the Immense Circle, mentioned there had been screams coming from the viewers as share of the ceiling got right here crashing down. A few minor injuries.
The London ambulance service, London fire brigade and Met police were called to the scene and road closures are in place around the theatre, Scotland Yard said. The theatre had been completely evacuated, it was stated in the police notice.
'Motorists informed to spend different routes'.
Writing on social media, one audience member claimed the ceiling collapse started "with some dripping" that "increased" until it "all caved in".
Wendell Pierce personally made sure the viewers at his play had been staunch and properly after share of a ceiling collapsed at Piccadilly Theatre.