But, you could infect a lot of people who would go back into the community and infect others.
OR, you could incapacitate all the regional hospitals before a terror attack so there are few to no services available for the injured.
OR, you could have a hostage situation like Beslen.
Hospitals are the very place in a small community that is already being trained (via mock-catastrophe drills) to deal with terrorism. There are even conferences specializing in scenarios available as "continuing medical education"--CME.
I am kinda thinking this year, I will not get a Flu Shot. I do not trust where these vacines are coming from.