US scientists 'solve' 9/11 conspiracy theory

US investigators said today they have solved one of the mysteries of the 9/11 attacks which has been a long-running source of conspiracy theories – the collapse of World Trade Centre building 7 (WTC 7).

The 47-storey trapezoid-shaped building, sat north of the World Trade Centre towers in lower Manhattan, was set on fire by falling debris from the burning towers on September 11 2001.