Were/are you aware of the fact that, during the 9/11 disaster, WTC building 7 fell down?

Last evening I watched a documentary on the attacks on 9/11, and in it somebody said that a big percentage of American people were not aware of building 7 collapsing that day.
Apparently that was due to the collapse only being broadcast sparsely.
Are you aware of it?
If so, were you so right then, or did you find out later?

I’m really not interested in pro or anti (whichever) conspiracy in this question, FWIW)