Karski was disguised and smuggled into the Warsaw Ghetto and a Nazi death camp near Belzec. Carrying with him the stories of inhumanity and genocide he witnessed, he traveled secretly to Washington, D.C., where he briefed Franklin D. Roosevelt about the Nazi's Final Solution.

After the war he became an American citizen, receiving a doctorate from Georgetown University, where he taught Eastern European Affairs for many years. In 1982 he was honored as a Righteous Gentile at Yad Vashem in Jerusalem, and in 1994, in recognition of his courage on behalf of the Jewish people, the government of Israel declared him an honorary citizen.

Karski wrote a book in 1944 titled "The Secret State," in which he described the destruction of European Jewry.

"We are profoundly honored to have this remarkable man as our keynote speaker," said John Rothmann, Yom HaShoah program chair.

This year's observance also will include a performance of songs from the Holocaust, a memorial service and candlelighting and readings by young people.

Sponsors are the Committee of Remembrance of the S.F.-based Jewish Community Relations Council and the Holocaust Center of Northern California. For information, call (415) 957-1551.