And Tim Mcveigh proved that with some fertilizer and gas you can take down a building in seconds.With a round of firearm, someone could take down a number of people in just seconds/minutes. A hammer could possibly take 2 people at the most, after which others would very likely jump him and take him down. Most would try to overpower someone wielding a hammer or knife, but a firearm, I don't think so. Assault weapons should be banned and removed from the general public.
And in 2001 19 people proved that you could take box cutters and take over 4 airplanes.
And in 2003 a man with a car proved that in seconds you could kill 9 people by plowing over them.