Two accidents have claimed international attention this summer. A Concorde supersonic airliner crashed after takeoff in Paris last month, killing 114 people. Today, the world is riveted by the unfolding disaster involving the Russian submarine Kursk, trapped on the floor of the Barents Sea with 118 sailors aboard. Three rescue attempts have failed, and time is running out.

Both incidents are far from the lives of ordinary people: Few if any of us are ever going to ride in a Concorde or a Russian nuclear sub. But they touch us, nonetheless. Not just because they are tragedies, but because they sharply illustrate our dependence on technology and remind us of a vulnerability in our lives that is usually obscured.

The Concorde has been in service for nearly 25 years. The plane was a high-visibility, prestigious joint project by the French and British governments. Flying on the Concorde -- the only supersonic plane in service -- was not for everyone, but it was an unmistakable status symbol for those who did.