Finally, there's practice. While rehearsing how to respond in a crisis often seems like an irritating time thief—think of how many groans there are during fire drills—it's the only way to make sure that in a real emergency, people respond without panicking.

All good advice, says Dr. Mitroff. "You have to have a crisis plan, and you have to have it fully integrated into the business," he says. "Every key area of the organization has to line up around it or it's worthless."

Secure the Perimeter and Assess the Situation Once a crisis has begun, anyone not part of the solution needs to be taken out of the fire zone to eliminate both second-guessing from above and resistance from below. "The guy who knows how to fix the situation with minimum impact has got to be in charge," says Barry.

Next, Barry says, it's important to immediately identify all of the moving parts of a situation, being careful not to make any sudden moves before the assessment is complete. "I look at a package; in the first three minutes, step by step I'm figuring out what I've got, and I'm not going to touch anything that I can't immediately recognize," says Barry. "All bombs have the same basic components, and only after you've figured out where they are and how they interact should you decide your method of entry."

As a classic example of worst practices, take the meltdown of Bear Stearns—which might have been avoided had leaders like Alan Schwartz not reacted with a series of uninformed public misstatements and desperate, knee-jerk measures—all before sitting down and seriously examining the nature of the impending crisis.

Learning From Your Mistakes Veterans of disaster know that lightning invariably does strike twice, and so learning from past catastrophes is critical to surviving future ones. Merrill Lynch C.E.O. John Thain drew a lesson from observing his colleagues at Lehman Brothers allow their credit-crunch-crippled firm to dwindle into a state of crisis. So as the pressure was being felt at Merrill, instead of holding firm and waiting for a bailout at the 11th hour, Thain sought a buyer for his company while it was still in decent health.

For Barry, the stakes were life or death. When he heard on 9/11 that the Twin Towers had been hit and went to the scene, he immediately recalled a key lesson from the first World Trade Center bombing in 1993, which he had also been at the scene of.

In the earlier bombing, Barry recalled that the front side of the towers had become a choke point, with upward of 50 rescue vehicles parked in a haphazard, interlocking fashion as emergency personnel raced to the scene.

This time around, Barry parked on the other side of the building where he'd have a clearer escape route. "When the tower fell, the vehicles parked out front were goners—they were all locked in, unable to move," Barry says. "The only reason I'm talking with you today is because I parked out back."