Thought this was an interesting article from european scientists about the building collapse on 9/11 https://www.europhysicsnews.org/articles/epn/pdf/2016/04/epn2016-47-4.pdf?inf_contact_key=750db96b807ba5f984418ed967314b14951b94a0cf4669ed424965189008b76a . Thanks @adam for reminding us and not letting this issue disappear