Members of the Student Nonviolent Coordinating Committee pray beside the ruins of a burned church near Dawson, Ga., in 1962.

Sept. 15 marks the anniversary of an infamous terror attack: the 1963 bombing of 16th Street Baptist Church in Birmingham, Alabama. On that Sunday morning, members of the Ku Klux Klan, a white supremacist group, planted dynamite on the east side of the brown brick building.

The bomb went off in the midst of Sunday school, at 10:22 a.m., murdering four girls: Addie Mae Collins, Cynthia Wesley and Carole Robertson, who were all 14 years old, and Denise McNair, who was 11. The blast injured 22 other churchgoers, including a 12-year-old girl, Sarah Jean Collins, who was blinded in one eye.

Originally published on theconversation.com, part of the BLOX Digital Content Exchange.