A man has died and another has been injured in an accident at the site of the new Wembley Stadium.
Work on the new stadium began 14 months ago
The London Ambulance Service was called at 0825 GMT on Thursday to the construction site in north London.
It says one man was declared dead at the scene and the other was taken to the Central Middlesex Hospital with leg injuries.
Work across the site has been suspended while an investigation is begun into the cause of the incident.
Police said it was believed a platform collapsed without warning and fell about 100 feet, trapping the men underneath.
They were freed by a team from the London Fire Brigade.
A spokesman for Wembley Stadium said: "I can confirm that unfortunately one person has been killed in an incident today.
"We're trying to establish the full facts at the moment with the construction contractor Multiplex, who are in charge of the project overall."
George Brumwell, general secretary of the building workers' union Ucatt, said: "This is a terrible tragedy and our sympathies are with the family. This is happening far too often in the construction industry."
The Health and Safety Executive said two inspectors had been sent to the site to investigate.
Construction work on the £757m complex began in September 2002 and the new stadium is due to open for the FA Cup Final in 2006.
A giant arch will be raised over the 90,000-seat stadium replacing the demolished twin towers as its emblem.