Twenty-five years after the September 11 attacks, researchers and engineers are still working to debunk conspiracy theories that emerged almost immediately after the World Trade Center towers collapsed. David Dunbar, an investigator who co-authored Popular Mechanics' widely cited 2005 debunking, told the Daily Mail that persuading committed conspiracy theorists remains extremely difficult, as many are too emotionally and psychologically invested in alternative explanations to accept expert findings. He traced much of the movement's origins to broadcaster Alex Jones, who claimed within hours of the attacks that the towers had been brought down by controlled demolition rather than the plane strikes.

Investigators from the National Institute of Standards and Technology found that the planes severed utility shafts in the towers' cores, spreading burning jet fuel that fed fires for 56 minutes before both structures collapsed within six minutes of each other. This directly contradicted claims that the impacts occurred too high to cause structural failure. Dunbar also addressed the popular claim that "jet fuel doesn't melt steel beams," explaining that while jet fuel's burning temperature does fall short of steel's melting point, the steel did not need to melt — it only needed to lose enough structural strength to bend and buckle, which prolonged fires achieved.