London's buzzing West End is home to nearly 50 major theaters and attracts massive crowds of tourists throughout the year.
The industry pumps £2 billion into the local economy annually as theater-goers splash cash on tickets, meals, transport and accommodation.
Investigators are still determining the cause of the collapse at the 112-year old playhouse.
Westminster City Council, which is responsible for the Apollo and other historic theaters, said the buildings are required to undergo rigorous roof safety checks every three years. About half the major theaters are more than 90 years old.
The Ambassador Theater Group said Friday it has begun additional ceiling and roof surveys at its London venues to reassure customers.