6. When we moved in 2005, I was horrified to discover just how much dust had settled beneath and behind furniture and in every hidden corner and crevice.

5. Every day, I wiped away the dust from every surface in the apartment, but every morning, a fresh layer of dust appeared, no matter how many washcloths we shoved under doors and around windows to keep it out.

4. We moved back on September 23. From our terrace, we could see crews digging 24 hours a day through the pile of twisted metal and charred steel. Fires smoldered at the site for months, and a sulfuric stench permeated the air.

3. Five days later, Christine Todd Whitman, the leader of the Environmental Protection Agency, assured us Lower Manhattan was safe and the air was clear. Ten days later, our landlord and officials from the city, state, and federal governments told us it was safe to return to our apartment.

2. We ran to what we hoped would be safety in Battery Park in the southern tip of Manhattan, only to be engulfed in dust and debris as the Twin Towers fell. For hours, we wandered in that choking cloud, until we were saved by one of the boats that spent all day ferrying people to safety.