While some people in the command center at the trade center seemed to know about it, and spoke about it on their walkie-talkies, they could not communicate with the ordinary tenants on the upper floors. Those people did not know that there was a way out by going down—that there was, in fact, a passable staircase. Most of them were dialing not into the basement command center but into the city’s 911 call center—and no one there was aware of the escape route.
