Book excerpt: What do Enron, the Space Shuttle Columbia and 9/11 have in common? Catastrophes don't 'just happen.' From Enron to the Space Shuttle Columbia to 9/11, virtually every disaster is the end result of a long series of small mistakes -- each one easy to overlook, and set in motion because people simply refused to believe the evidence staring right at them. Robert E. Mittelstaedt first identifies the common factors beneath massive failures ranging from Watergate to Firestone Tire, Three Mile Island to 'New Coke.' Why did they happen? What could have prevented them? How did they spiral out of control.