'Day of service' in honor of 9/11

"We hope to rekindle the spirit of unity and compassion that followed the terrorist attacks," he told a news conference near the site of the World Trade Center.

Paine joined other members of the 9/11 community to unveil a national campaign to build support for the privately funded effort.

They urged volunteers to use a Web site launched Thursday that shares service projects and opportunities throughout the country.

Volunteers may choose any kind of activity, from working in a Harlem community garden and mentoring school children to performing music.

Organizers said they hope the 10th anniversary of the attacks in 2011 will mark the single largest day of service in U.S. history.

This year's volunteers include prominent musicians staging a tribute concert on Sept. 11. Gavin DeGraw, The Roots and others will perform at Manhattan's Beacon Theatre, with free tickets going to relatives of victims, recovery workers, volunteers and those who served tours in the military after the attacks. The rest of the tickets are being distributed by lottery.

The show will also feature actor Gary Sinise, talk-show host Jimmy Fallon, the Harlem Boys and Girls Choir and singer Anjulie.

The lineup of nationwide volunteer events will be "spontaneous," organizers said.

"Families are invested in creating living legacies for their loved ones," said Mary Fetchet, whose son Brad died in one of the towers.

The idea of establishing 9/11 as a National Day of Service was first conceived in 2001 by the founders of MyGoodDeed, a nonprofit started by friends and relatives of 9/11 victims. They are working with ServiceNation, the National September 11 Memorial & Museum and the Corporation for National and Community Service.

In April, Obama authorized the establishment of 9/11 as a National Day of Service when he signed into law the Edward M. Kennedy Serve America Act.

Thursday's news conference was held just hours before the late senator's body left his Hyannisport, Mass., home for a series of memorial rites followed by his funeral Saturday. Kennedy, who died Tuesday of a brain tumor, had co-sponsored the bill.