James Fetzer is the founder of "Scholars for 9/11 Truth" and has been investigating 9/11 for many years. He makes a compelling case that the Twin Towers were destroyed by mini-nukes (which also helps explain the huge spike in cancers for those working near ground zero). On the other hand, 9/11 expert Judy Wood has a competing high-tech theory which involves the use of Directed Energy Weapons (DEW). Others believe thousands of metric tons of nano-thermite was used to collapse the towers into their own footprint. You decide.