An investigation is under way to find out why scaffolding collapsed on a building site in Milton Keynes, injuring three workers.
The Health and Safety Executive and the contractor's own officials are looking into how 14 storeys of scaffolding at the hotel and housing site came down.
Two of the injured are in a serious condition and a third is stable.
The managing director of site contractors McAleer and Rushe, Eamonn Laverty, blamed high winds.
Up to 200 workmen were at the Witan Gate site but many were on a lunch break when it collapsed.
A new Jurys Inn Hotel, due to open in June, and homes were being built. All building work has stopped and police are treating the site as a crime scene.
Officials said they thought all those at the site had been accounted for.
Mr Laverty said the incident had been reported to the Health and Safety Executive and it was conducting an investigation, as was the company's health and safety officials.
Eyewitness Nick Reynolds said: "It came down like a pack of cards", while others said it sounded like a roll of thunder.
Chief Inspector Andy Stanton, of Thames Valley Police, said the fire brigade had used heat-seeking equipment to search the site but more specialist equipment would be used to comb the wreckage.
The three people who were rescued were taken to Milton Keynes General Hospital for treatment.
A number of others were treated for minor injuries at the scene.