The disaster in Haiti shows once again that even amid the worst devastation, there is always hope.

I saw that this week in Port-au-Prince, where the United Nations suffered the single greatest loss of life in its history. Our headquarters in the Haitian capital is a mass of crushed concrete and tangled steel. Upon seeing it, I wondered: How could anyone survive? Yet moments after I left the scene on Sunday, rescue teams pulled out a survivor -- who had been buried five days without food or water.