What happened to Building Seven? Most people have never heard of building seven. Most people have no idea that a third building collapsed on September 11, 2001. Some 1500 architects and engineers have an unconventional view of what happened. At minimum, the collapse of Building Seven is somewhat of a mystery. The National Institute for Standards and Technology has refused to release the data on this event. All the data regarding September 11th and building 7 should available to the public. Watch the video below and research the topic some more if you are so inclined.