Our nation was irretrievably transformed by 9/11 -- and yet there remain troubling questions about what really happened. Why did building WTC-7 fall, though no aircraft struck it? Fire alone had never before caused a steel skyscraper to collapse. Why did no U.S. military jet intercept the wayward aircraft? Why has there been no investigation of BBC reports that five of the alleged 9/11 hijackers were alive and accounted for after the event? A group of experts and academicians devoted to applying the principles of scientific reasoning to the available evidence [and] 'letting the chips fall where they may,' last week accused the government of covering up evidence that the three destroyed New York City buildings were brought down that day by controlled demolition rather than structural failure. The group, called Scholars for 9/11 Truth, has a website, www.st911.org.