Had we seen an earthquake, or the results of a powerful storm, the devastation and loss would have been awful — but our country has seen terrible tragedies before: fires, earthquakes, floods, and hurricanes. We prayed for the lost, rebuilt for the survivors, and strengthened our laws, dikes, weather warnings and earthquake predictors. We prepare for an eventual recurrence of acts of nature…
But 9-11 was not a natural catastrophe: these events were deliberate, conceived, organized and ruthlessly executed by human beings. And so, their significance must be assessed differently — and the actions to prepare for next time must be different, also.

Seton Hall Address (2002)