LONDON, Dec. 20 (UPI) -- The Society of London Theatre Friday carried out checks of its 52 historic theaters following the roof collapse at the Apollo Theater that injured 79 people.
Part of the century-old theater caved in during a performance of "The Curious Incident of the Dog in the Night-Time" Thursday evening.
"It could have been a lot worse -- there were about 720 people in the auditorium at the time and a large area of the ceiling came down," London Fire Brigade's Kingsland Station Manager Nick Harding said.
Authorities have launched an investigation into the cause of the collapse, the Wall Street Journal reported.
"What we have to remember is there have been theaters in London for hundreds of years. ... There's never been an incident like this in living memory and we hope there never will be one again," said Mark Rubinstein, the president of the society.
The Westminster City Council said it was on site at the Apollo to look into the incident.
"However, we can say that the Apollo's health and safety checks are up to date," Nickie Aiken, the council's Cabinet Member for Community Protection said. "Each historic theater is unique and we have no reason to believe this is anything other than an isolated incident."
Investigators tried to determine if rains earlier in the evening were a factor in the collapse, CNN reported.
The Westminster City Council said theaters like the Apollo undergo "rigorous roof safety checks every three years."
