The hundreds of theatergoers who packed into Central London’s historic Apollo Theatre on Thursday night were expecting to watch a mystery.

But about 40 minutes into the play, shortly after 8 p.m., they got a drama instead, CNN reports.

“One of the actors said, ‘Watch out!’” said one woman. “We thought it was part of the play.”

It wasn’t. Instead, it was part of the century-old structure’s ornate plaster ceiling, which tumbled five stories onto the theatergoers, injuring scores of them, seven seriously, officials said.

“We heard a creak, somebody screamed, somebody from over there said, ‘Look out!’ and then the ceiling kind of creased in the middle and then just collapsed,” said Hannah, who with her husband had snagged one of the last pairs of tickets to the performance in the 775-seat theater.

Though she said she herself felt “slight panic,” she credited those around her for keeping their calm. “It wasn’t every man for himself,” she said, noting that several of her fellow theatergoers checked on those around them. “Everyone was looking out for each other, and in a couple of minutes, everyone was out.”