Debris from planes and buildings hit St. Peter's during the terrorist attacks.
Dolan said Sunday that the church "became a sanctuary of prayer, refuge, outreach, mourning and healing."
Adds Dolan: "On a day we could have cursed, we rather prayed."
Egan said "evil had its moment of triumph" on that day, leaving an "anniversary that stings and sears the soul."
But he witnessed heroism by doctors, police, firefighters and other emergency workers.
Egan said that for days and weeks, New York "became a huge outdoor house of worship," marked by heroism, "total selflessness" and "a love of neighbor."