More than 80 people were injured Thursday when part of the roof at London's Apollo Theater collapsed during a performance.

The city's ambulance service said its personnel assisted 88 people, including seven who were hurt seriously and transported to hospitals.

One of the 720 people attending the performance of "The Curious Incident Of The Dog in the Night-Time" told the BBC of hearing a "crackling" noise just prior to the collapse at 2015 GMT.

Pedestrians who were in nearby Piccadilly Circus at the time of the accident recounted seeing people fleeing the theater covered in dust, some with visible injuries.

"The entire dome roof fell down on the audience just in front of us," Amy Lecoz, who was watching the play with her two teenage children, said. "We were protected by the balcony above and we ran. People started screaming."

Built in 1991, the Apollo has 775 seats distributed among four different levels. EFE