Last month, Lisa Yvette Sullivan confided to a friend and colleague that her fledging youth organization, LISTEN, was about to come into its own. “LISTEN can’t just be about me,” her friend remembered Sullivan saying. “These people have to take it over, and make it work. I’ve got a talented bunch of people, and they can really make it work.”

Sadly, Sullivan won’t be around to see it happen. The dynamic youth organizer and leader in the African-American community died on October 1 after suffering a brief and unexpected illness. She was 40.

An activist and organizer since childhood, Sullivan founded the Local Initiative Support Training and Education Network, or LISTEN, a national youth organizing network based in Washington, D.C., in 1998. By providing training and technical assistance to burgeoning nonprofits focused on youth work, LISTEN has built a wide-reaching network for activists ranging from hip-hop revolutionaries to foes of the prison economy. Her associates in New York included the South Bronx youth activism group Youth Force and the Prison Moratorium Project.

Her work earned her title as one of “100 to Watch in the New Millennium” in Washingtonian magazine this past January, and the NAACP awarded her its Roy Wilkins Youth Leadership Award in 1996. Just last week, New Haven’s Board of Aldermen passed a resolution offering condolences for Sullivan, noting the voter registration drives she led and the campaign she helped run for the city’s first African-American mayor while she studied for her Masters degree at Yale University.

“Lisa was one of the few people I’ve ever met to whom the title visionary could rightly apply,” said Neil Carlson, editor of Responsive Philanthropy and a LISTEN board member.

Before launching LISTEN, Sullivan founded the Black Student Leadership Network, served as director of the field division at the Children’s Defense Fund and worked as a consultant to the Next Generation Leadership Program at the Rockefeller Foundation.

“The one thing that does give me hope is that she left behind this organization whose goal was really her life’s work,” said Kathleen McFate of the Rockefeller Foundation, which helped fund LISTEN. “Everyone involved is really there in terms of making sure this continues.”