How are fallout shelters similar to the government trying to secure the critical infrastructure of the United States post-9/11?

Please see the below questions that I would like to have answered. 1200+ word count/ 3 scholarly sources (one sources per paper) The textbook is attached with additional read links as well.

Homeland Security Act Summary:
http://www.thepoliticalguide.com/Issues/Homeland_Security/

Patriot Act Summary:
http://www.thepoliticalguide.com/Issues/Homeland_Security/

Question 1. How are fallout shelters similar to the government trying to secure the critical infrastructure of the United States post-9/11?

Question 2. Was the exercise in financing fallout shelters similar to that of trying to finance homeland security preparedness today?

Question 3. Should the government be entirely shielded from lawsuits? How does doing so allow the government to continue functioning? How would you argue with someone who says that suing the government can work to make it a better organization?

Sorry for the short notice, Family Emergency!