What took the Governmen planes so long to respond after the plane crashed into the building in N.Y.?

Question

There was a small plane that crashed into an apartment building on Monday, and the news said: "It only took the jets 10 minutes to respond". In those 10 minutes, that building COULD have been destroyed by yet another plane as the planes that attacked the WTC were just minutes apart. So, what took so long on the response from the Government when the plane hit the building?

Answer 1

will ask NORAD.