Hundreds of worshippers packed an Alabama church on Sunday to honor four young girls killed 50 years ago in a bombing by the Ku Klux Klan that became a defining moment in the U.S. civil rights movement.
Bells tolled at the precise moment the blast ripped through Birmingham's 16th Street Baptist Church, killing 14-year-olds Addie Mae Collins, Carole Robertson and Cynthia Wesley, along with 11-year-old Denise McNair.
Later, the Rev. Arthur Price taught the same Sunday school lesson on forgiveness that was heard the morning of the bombing.
President Barack Obama, in a written statement, called September 15, 1963 a "horrific day" for the city and the country that ultimately galvanized national support for the passage of the Civil Rights Act of 1964.
That federal legislation outlawed discrimination based on race, ethnicity, religion and gender. It also brought an end to so-called Jim Crow laws that enforced rigid segregation in much of the American South.
One of the Klansmen convicted years later in the bombing remains imprisoned. Two others died in prison.
Former U.S. Secretary of State Condoleezza Rice, a Birmingham native who attended school with victim Denise McNair, headed a list of speakers set to participate in a Birmingham commemoration later in the day. U.S. Attorney General Eric Holder also was on hand.
The U.S. Congress last week posthumously awarded the victims the Congressional Gold Medal -- the highest honor bestowed on American civilians.