Fourteen storeys of scaffolding have collapsed at a building site in Milton Keynes, trapping several people and injuring up to 20.
Two walls of a Jury's Hotel being built by Northern Irish contractor McAleer & Rushe collapsed on Tuesday, pulling scaffolding down with them. Thames Valley Police said a number of people were believed to be trapped in the wreckage.
One eyewitness told the BBC: "It's a massive site. There are six tower cranes but the scaffolding is just one pile of matchsticks."
McAleer & Rushe had issued no statement about the cause of the collapse as Building went to press, but it is understood that high winds were blowing when it happened.
The Health and Safety Executive sent three inspectors to the site.