On a hot June evening in 1964, Mickey Schwerner, James Chaney and Andrew Goodman were ambushed by the Ku Klux Klan and killed as they left town.The atrocity became a seminal moment in the civil rights movement. Yet 60 years after the killings, some people in Philadelphia worry that the country is forgetting what was learned along the way. Others wonder what the past is owed — and for how long. They talked with Susan Levine this spring about their community’s painful legacy of racism.This episode was produced and mixed by Bishop Sand. It was edited by Lucy Perkins. Thanks also to Allison Michaels.