VP is a little pushy...
I'm sure they will make this the wrong decision, but shutting down the city completely and imposing a curfew would pretty much trap the terrorists wherever they are. Bring in every guard troop you can find to fly over the city, re-task the satellites, turn on the traffic cameras, and handle this.
Remember 9/11. After they realised a few planes were hijacked, we shut down the entire air traffic control system, forcing all the planes to land, so we could tell which ones to shoot. That was real life, that's how you have to handle this stuff -- none of this "we can't let people know what is going on" stuff.
It still amazes me that we are to believe that people are going about their business as usual in LA after: 1) terrorists take over and blow up an airport terminal; 2) Terrorists attack and blow up a motorcade with the russian president and the first lady; 3) a poison gas attack hits a mall, and 4) a poison gas attack hits a hospital.
There is no way to keep that quiet, and LA should have been shut down hours ago.