The audience in the Apollo Theatre had nicely settled into their seats to watch the acclaimed performance of The Curious Incident of the Dog in the Night-Time when suddenly pieces of the ceiling began raining down.
At first some thought it was part of the show. That changed when the actors stopped and began pointing to the ceiling as large chunks of the ornate plaster began falling off, hitting people in the upper levels and stalls that run along a balcony. Dust filled the 112-year-old theatre in London's west end as more than 700 people rushed for the doors.
Police said some were too injured to move, leaving them trapped in their seats.
"The entire dome roof fell down on the audience just in front of us," Amy Lecoz, who was at the theatre with her teenaged children, told the BBC. "We were protected by the balcony above and we ran. People started screaming. We thought it was water … We thought it was a part of the show. I grabbed my kids and ran."
Martin Bostock remembers the moment he realized something was wrong.
"All the actors reacted, we saw all the actors looking up above us and pointing, looking horrified and then things started falling and smoke, and I thought it was part of the show until something hit me on the head very hard," he said.
Police, fire and ambulance officials rushed to the scene shortly after 8 p.m., setting up a makeshift treatment centre in the Gielgud Theatre next door. "When I arrived it was dark and extremely dusty and people were lying on the floor of the theatre," Incident Commander Maria Smith told reporters.
About 51 people, including at least five children, were sent to hospital in a convoy of three buses. Seven had serious injuries.
One seriously injured woman was loaded into an ambulance wearing a shock blanket, accompanied by another woman who was walking with an ice pack on her head.
"It has been confined to some heavy ornate plastering typical of what you would expect to find in a theatre in the west end of this age," said deputy assistant fire commissioner Brian Ellis.
"It has fallen from the roof level, so above the upper circle. It has fallen down to the upper circle and stalls."
Chief Superintendent Paul Rickett added that there were no deaths and no suggestion of any criminal activity.
The area around the Apollo, which is not far from Piccadilly Circus, was packed with Christmas-time revellers, most oblivious to the scene unfolding down the road. Some wondered about the fuss, assuming it was part of another show.
The Apollo was built in 1901 and has 755 seats and the third tier is considered the steepest in London.
The theatre's owner, Nimax Theatres, called the accident a "shocking and upsetting incident."
The theatre is among the best-known in London and had been showing award-winning production of The Curious Incident Of The Dog In The Night-Time since March.
"It's been horrifying sitting here watching what has been happening at the Apollo this evening. I'm hugely relieved that no one has died," said author Mark Haddon, who wrote the book that the production is based on.