The principles of crisis management are the same, whether you're defusing an I.E.D. or the SEC. You have to keep a cool head, secure the perimeter and assess before you do anything that might blow up in your face. And you have to prepare for a crisis long before the bomb drops. There's at least one important difference, says business professor Ian Mitroff:"In business, crisis begins in one place and a chain reaction results. You usually can't defuse one thing and call it a day."