Twenty-five years ago, a Sunday school lesson about forgiveness ended with the blast of a bomb planted by a Ku Klux Klansman, and four black girls lay dead. Since then, Birmingham has learned much about forgiveness.

The bombing at the 16th Street Baptist Church sparked outrage that helped fuel the 1960s civil rights movement, which eventually eased the bitter racial divisions in this city, speakers noted at a memorial service on the anniversary Thursday night."There has been a turnabout in human relations in this city, which now has an improved image," the Rev. John H. Cross told a racially mixed congregation of 1,400 people gathered to remember Cynthia Wesley, Addie Mae Collins and Carol Robertson, all 14, and Denise McNair, 11.

"Twenty-five years ago the only blacks at City Hall were elevator operators and janitors. Now we have Richard Arrington as mayor," Cross said.

Cross was the church's pastor on Sept. 15, 1963, when the bomb, planted beneath basement steps, exploded after a Sunday school lesson on the theme of a love that forgives. The girls were killed as they were preparing to take part in a youth day program. Twenty-two other people were injured.

In a service that featured freedom songs of the civil rights movement, Arrington, who is in his third four-year term, said "the torch that we raise tonight is raised by two hands - one black and one white."

"We have the power to transcend that tragic event. We are determined it will have a redeeming quality."