Former President Clinton asked to meet privately with Columbine High School (search) families before speaking Tuesday at a fund-raiser for a memorial to victims of the 1999 massacre.

It will be Clinton's third visit to Denver to talk about Columbine. He was invited to speak at the fund-raiser after he asked a friend about progress on the memorial, said Bob Easton (search), chairman of the Columbine Memorial Committee.

Easton said Clinton requested private time with Columbine families.

Clinton was president when Eric Harris and Dylan Klebold shot and killed 12 students and a teacher before taking their own lives April 20, 1999.

He traveled to Colorado and spoke to Columbine students a month after the massacre, and returned about a year later to support a ballot proposal to tighten state rules on weapons sales at gun shows. The measure passed easily that fall.

The former president was already scheduled to be in Denver on Tuesday to promote his new book, "My Life." He agreed to waive his $100,000 speaking fee for the fund-raiser.

About 700 people and companies are paying $250 a ticket for the fund-raiser, and donations of up to $50,000 were expected. The committee has raised $600,000 in cash and has additional pledges of labor and in-kind contributions, Easton said. The goal is $2.5 million.

The memorial would cover one acre on a hill above the school.