I don't understand how they could all just sit there and watch. The guy had a knife, not a gun. They all could have just ambushed him and there wouldn't have been much he could do about it.
Did you guys know that when the VT massacre occurred, six of the students inside that building at the time of the shooting had handguns either in their car or in their home (don't know if they had a CWP, but I'd be willing to bet they did if their guns were sitting in their car)? I just found that out tonight. So had they been allowed to carry on campus, I'm sure at least a couple of those students would have been armed inside the building that morning and would have been able to stop Cho before he took 32 lives.