In August 2005, David Bentley prepared to go to war.
He had been in the National Guard in his 20s. Now in his 40s and recently divorced, he re-enlisted and was ready to join the many Louisiana National Guard troops deployed overseas following the Sept. 11, 2001, attacks.
Then, on Aug. 29, Hurricane Katrina hit the Gulf Coast with brutal force, killing 1,400 people and displacing an estimated 1.5 million…