Ask just about anyone &045; your sister, your boss, even a perfect stranger &045; and they can probably tell you detail by detail what they were doing on Sept. 11, 2001.

As we commemorated the sixth anniversary of this heartbreaking event yesterday, Americans everywhere felt those memories flood back.

Just weeks ago, a flood of images reminded us, too, of the catastrophe of Hurricane Katrina. Thousands of lives were lost and hundreds of thousands more were changed forever.

The greatest tribute we could pay to the victims of these tragedies would be to make time for those of our fellow Americans who need us most. Thousands have been to New Orleans and the Gulf Coast to muck out houses and to help rebuild. Millions have donated money to help the families of those lost in 9/11.

We can never do enough.

There is still rebuilding to do throughout our country. Rebuilding of lives damaged by fire, disease, financial crisis or natural disasters. All Americans can contribute by volunteering even small amounts of their time with church ministries or with national projects such as Americorps, Special Olympics, Habitat for Humanity, Second Harvest and more.

Sept. 11 and Hurricane Katrina awoke the spirit of community in the hearts of many Americans. The challenge is to not let that spirit diminish with time. We should want our legacy as Americans to shine through as a country of people who care about their neighbors and who only allow adversity to make them stronger as a community.