$@!*&!#%%? are you supposed to do?

People reported that the CTC shooter fired off dozens of bullets and chaos as people realized what was going on.

What the $@!*&!#%%? are you supposed to do, when someone runs into an enclosed area with a semiautomatic weapon, with a high capacity magazine, and just starts shooting?  What if there were multiple shooters, all with semiautomatic weapons and high capacity magazines?

How did the shooter die?  Self-inflicted wound after his gun jammed.  In other words, it could have been a lot worse; luck was all that stood between a massive death toll to the (currently) two dead.

$@!*&!#%%? man...$@!*&!#%%?.