A new report challenges the official explanation for the collapse of World Trade Center Building 7 on September 11, 2001. It claims that the fires caused by the debris from the nearby Twin Towers could not have been responsible for the destruction of the 47-storey building.

The building, which contained offices of several government agencies, fell after burning for seven hours. The National Institute of Standards and Technology (NIST) concluded that it was the only steel skyscraper in history to collapse solely due to fire.

However, a team of engineers from the University of Alaska has conducted a four-year study that contradicts the NIST findings. They presented their preliminary results at a symposium in New York, where Dr J Leroy Hulsey said: “Fire did not cause the failure of this building.”

The report will fuel the suspicions of conspiracy theorists who believe that the three World Trade Centre buildings were deliberately demolished with explosives. Some allege that the US government orchestrated the attacks to justify its military interventions in the Middle East.

No other steel-framed high-rise buildings have collapsed because of fire, even when the fires were much larger and longer-lasting than those in WTC 7. There were no casualties reported in the building, which was evacuated after the planes hit the Twin Towers.