(CBS News) -- A turning point in the Civil Rights movement came 50 years ago when members of the Ku Klux Klan bombed a black church in Birmingham, Alabama.
Four young girls were killed.
And nationwide outrage led to the passage of the Civil Rights Act one year later.
Today, President Obama signed a law to honor the victims— Denise McNair, Addie Mae Collins, Cynthia Wesley and Carol Robertson with the congressional gold medal.
A fifth girl survived the blast.
For Sarah Collins Rudolph, entering the 16th Street Baptist Church is still painful - because this is where 122 sticks of dynamite blew a gaping hole in the wall and killed four girls - including Sarah's sister Addie.
She spoke about it for the first time on camera, with CBS News' Bill Plante.
Sunday School had just ended. It was 10:22 a.m., and the five girls were in the bathroom.
"That is when I heard something go boom! It was so loud and all I could do was jump and say Jesus," said Sarah.
"And all of a sudden I began to call Addie. And I said Addie, Addie. But she never answered," she said.
Addie and the three other girls were dead.
"I just kept wondering, why did they kill Addie? Addie never did anything for someone to kill her," said Sarah.
Rudolph was showered with debris and flying glass. She lay in the hospital, eyes bandaged, for nearly three months. Doctors had to remove her right eye.
She now wears a prosthesis and still has pieces of glass in her left eye.
Fifty years later, Sarah still suffers from what happened.
"When I would go to bed at night, I would just cry all night long, just why did they kill those girls," said Sarah.
However, Sarah said she feels no bitterness.
"Being bitter won't bring the girls back, won't bring my sight back. So I had to forgive because it was what God wanted me to do," she said.
A survivor's forgiveness— overcoming the evil that trespassed a sanctuary.