Professional crisis communicators watched the news conferences with dismay. Deflecting blame is not helpful if politicians want to build trust with the public, they say.

The Homeland Security chief denied that a memo she issued in June requiring her to approve FEMA expenditures over $100,000 caused the agency to move more slowly.

Ms. McKay is a war and humanitarian-focused international correspondent and author of 'Only Cry for the Living: Memos from Inside the ISIS Battlefield,' 'Afghanistan: The End of the US Footprint and Rise of the Taliban Rule,' and 'The Dictator's Wife.'