Airlines and September 11

As a result of the September 11, 2001 terrorist attacks on the world trade center, and the subsequent plummet in airline travel, airlines worldwide lost $12 billion in 2001 and will lose an estimated $6 billion in 2002. Four airlines around the world went into bankruptcy, and many are on the brink.
Were these dire consequences preventable?
El Al, the Israeli airline, has never been successfully hijacked. Their secret?
Profiling
Integration with intelligence agencies