LONDON -- At least 76 people were injured Thursday when a "huge piece of plaster" broke off from the ceiling of London’s Apollo Theatre, crashing into the audience and bringing down sections of a balcony, officials said.
Several victims were initially trapped under the debris from the theater in the British capital's West End, which was packed with about 720 people for a performance of "The Curious Incident Of The Dog in the Night-time."
“The people from the first row were pointing at the ceiling,” journalist Tom Chesshyre, who was in the audience, told ITV’s Daybreak program on Friday. “We thought initially there might have been a drip coming down or some water or something and then we realized it was more than that and people began to really want to move out of the aisle altogether. The panic spread very quickly amongst the rows where I sitting.
He added: “As we got up we saw a huge piece of plaster about three meters wide and three meters long with elaborate stucco from the ceiling just plunge down below. It was terrifying and the dust immediately rose.”
Journalist Simon Usborne, who was also in the audience, told Daybreak that the falling debris was "like watching a waterfall from behind, an avalanche."
He added: “Our only view of the falling debris was this curtain of grey dust, containing larger objects that suddenly filled the space in front of us, obscuring all view of the stage."
Seven people were seriously injured by the falling debris and 69 others were treated, the London Ambulance Service said. The added that 51 suffered minor injuries and were walking wounded after the incident which was first reported at around 8:15 p.m. local time (3:15 p.m. ET).
Police and fire officials said it was too soon to say what had caused the partial collapse of the ceiling, but that a full investigation is being carried out.
The Apollo Theatre first opened its doors in February 1901. The auditorium is split on four levels with a total of 775 seats.
Mark Haddon, who authored "The Curious Incident Of The Dog in the Night-time" book which the play is based upon, tweeted that he was "hugely relieved that no-one had died."
British Prime Minister David Cameron praised the city's emergency services — who were on the scene within three minutes — for their "fast work" in helping the injured.
London Mayor Boris Johnson also thanked emergency services for their "incredible response in very difficult conditions."
“In my time as a fire officer I’ve never seen an incident like this," Nick Harding of the London Fire Brigade said.
The Associated Press contributed to this report. Becky Bratu reported from New York.