While air travel security may look vastly different now than it did before the Sept. 11, 2001 terror attacks, one former TSA administrator said that he's afraid not of a single attack, but of a "failure of imagination" on the part of U.S. security officials going forward.
"I think that's the most haunting thing, failure of imagination," former TSA administrator Kip Hawley told ABC News. "If you can't imagine it... How do you stop it?"
WATCH: Ten Years After 9/11, Are We Safer?
A recent report...Full Story