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 . `` One of the actors said , 'Watch out ! ' '' said one woman . `` We thought it was part of the play . '' It was n'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 was n'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 . '' The London Fire Brigade 's Kingsland Station Manager Nick Harding said about 720 people were inside when a section of the ceiling collapsed on the theatergoers , taking parts of the balconies with it . An ambulance official said a total of 76 people had been injured , though many of them were treated at the scene and released . `` It was like slow motion , '' said one girl , who initially thought the sound of the falling ceiling was sound effects , but soon learned otherwise . `` It just kinda came down . '' Harding said what fell was a 10-meter-by-10-meter square section of the ceiling , and that it dragged down balconies with it . `` You initially thought it was part of the play and then you could feel things on you , '' said an older woman . `` The dust that came down -- you could n't see in front of you . '' Metropolitan Police said those who were seriously hurt had been taken to hospitals in central London . None of the injuries appeared life threatening , one official said . Within an hour , a spokesman for the fire department said everyone , including those who had been hurt , had been evacuated from the building . Martin Bostock , who was with his wife and two children , said he thought the cave-in was part of the show until something very hard hit him on the head and chaos and panic erupted . `` You could n't see across the room because of the dust , which we were all breathing in , '' he told CNN . `` It was absolutely horrific and very terrifying . I was with my wife and two kids . Thank God , we got out . '' The Apollo is located next to Piccadilly Circus in the Soho district , which is usually packed with tourists , shoppers and diners at theater time . Within minutes , paramedics arrived carrying stretchers as police cordoned off the area . A few minutes later , some of the paramedics emerged from the theater , their stretcher full ; others helped someone limp out of the building . Many of the injured were taken initially to the nearby theaters for an initial assessment of their condition by medical workers . The initial police assessment of the collapse was that it was an accident . `` There is no suggestion at this stage that this was as a result of a criminal act , however , at this stage we are keeping an open mind , '' Metropolitan Police said in a statement . Outside the Apollo , the street was packed with dozens of police , fire and ambulance vehicles as well as well-dressed theatergoers , some of their faces darkened with dust . `` The Curious Incident of the Dog in the Night-Time , '' which was adapted to the theater from the 2003 mystery novel by British writer Mark Haddon , is about a 15-year-old boy 's investigation into the death of a neighborhood dog . Ticket prices at the four-level theater , which opened its doors in 1901 , included a £1 ( $ 1.64 ) `` theatre restoration levy , '' the theater 's website said . It was not immediately clear whether the ceiling was part of the restoration of the building , which is owned and operated by Nimax Theatres . In a statement , a spokesman said the company would `` continue to cooperate fully with the authorities to establish exactly what happened tonight . '' Prime Minister David Cameron , in a tweet , commended the fast work of emergency services . Now , what started as a mystery and veered into drama has again become a mystery , as engineers try to determine what caused the collapse .
`` One of the actors said , 'Watch out ! ' '' audience member says . Comment: `` The Curious Incident of the Dog in the Night-Time '' was playing . Ticket prices included a 1 pound `` theatre restoration levy ''