Apollo Theatre ceiling collapse 'caused by heavy downpour' The owners of all the major venues in London held a meeting on Friday at which they confirmed their safety inspections and certificates were up to date, and pledged their full co-operation to the authorities. Mark Field, the MP for the Cities of London and Westminster, which includes the West End, said he had been briefed by the emergency services and the working theory was that heavy rain caused the collapse. He said: "Probably what happened was that we had this flash flood-type thunderstorm and there may have been a problem with the drainage and water settled on the roof. I'm sure there will be some urgent checks being made at other theatres on drainage, but the overall message is that it's business as usual. It's important to remember that although these buildings go back to Victorian times there has been a significant amount of investment in recent years to bring them up to date. MeteoGroup, a weather forecaster, said there had been an abnormally high concentration of rain, hail and lightning strikes in London between 7pm and 9pm on Thursday. Some 0.3 inches of rain fell in just one hour in part of the capital, representing nearly 15 per cent of the normal monthly total for December. Members of the emergency services work at the scene of the ceiling collapse at The Apollo Theatre in London (REX) About 720 people had squeezed into the Apollo on Shaftesbury Avenue to enjoy a pre-Christmas performance of the acclaimed stage adaptation of Mark Haddon's award-winning novel The Curious Incident Of The Dog In The Night-Time. The cast, who include Jo Dockery, the sister of Downton Abbey star Michelle Dockery, were about 45 minutes into the play when cracking and creaking noises were heard inside the Grade II-listed theatre. Suddenly a huge chunk of plaster from the ceiling plummeted onto the seats below, knocking down a section of the balcony and landing on the main stalls. Panicked theatregoers screamed as they pushed their way to the exits through the debris and a thick cloud of dust. Hanan Mohammed, 18, from north London, was part of a school group of A-Level psychology students and their teachers who had gone to see the play as an end-of-term treat. She described seeing traumatised children as young as ten outside the theatre with their faces blackened by the dust so that they looked like "chimney sweepers." The emergency services arrived on the scene quickly. Paramedics treated a total of 79 casualties, including 47 walking wounded who were taken to hospital as a precaution and nine people who had suffered serious head or back injuries. Westminster Council declared on Friday that surveyors had found the structure of the ceiling to be "sound" but announced it would be carrying out checks on all the area's historic theatres. Nicola Aiken, the council's cabinet member for community protection, refused to comment on suggestions that the extreme weather caused the collapse, but said Westminster might review its policy of only checking historic theatres" ceilings every three years. Scotland Yard has ruled out terrorism or deliberate sabotage, saying it was satisfied that the collapse of the ceiling was not caused by a "criminal act." Chief Superintendent Paul Rickett, head of policing in the borough of Westminster, warned that it could be several days before bags left in the theatre as audience members fled could be returned to their owners. A spokesman for the Society of London Theatre said it was an "extremely rare" incident, adding: "Our theatres entertain over 32,000 people in central London every night and all theatres take the safety of their audience, performers and staff very seriously."