This was a really popular conspiracy theory following 9/11. I lived in New York back then and remember this stuff.
The other really popular one was that all the cab drivers knew about the attacks in advance and avoided going near south Manhattan.
You're old enough to remember 9/11. That's reassuring for a newer member. Usually they don't-- if they were alive at the time. 
Yeah, I was nine, just old enough to remember everything that happened and for the entire school to just be flooded with rumors and stories.
I have an enduring claustrophobia from all the stories and images I imagined of people trapped under the rubble. After 9/11 there were tons of stories about firefighters searching through the rubble for trapped survivors. It's really bad. I got really uncomfortable during the last Hunger Games movie, when they're all underground.
