North Tower
During everything that is happening with Flight 11, the airtraffic controlers becoming aware of what is happening, and them scrambling fighter jets to find out what is happening with Flight 11, the business district of New York is coming to life. Those in the North Tower are just going about their day like it's any other day. Then, everyone is stunned when the first plane hits at 8:46am.
It is also during that time that firefighters, police, and anyone who can is being dispatched to the scene to help with what and how they can. The plane had hit between floors 93 and 99, causing those who were there on impact, including everyone on board were dead. Those above floor 99 and trapped, as the stairs in the North Tower are on the side where the plane hit, and the service elevator can no longer be in service. The firefighters that had made it to the scene did not know what to expect, but knew that there were people who needed help.