Their bodies were found in a basement restroom. More than 20 people were injured from the attack.

Although most of the people inside were able to escape, four young girls -- Cynthia Wesley, Addie Mae Collins, Carole Robertson and Denise McNair -- were killed.

On the morning of the bombing, there were about 200 congregants attending services. The bomb exploded on the church's east side, causing its interior walls to cave in.

Rice grew up in Birmingham and was 8 years old at the time of the bombing. She was friends with one of the victims and recalled the incident Friday. "As an 8-year-old, you don't think about terror of this kind," she said at a gathering of civic leaders in Birmingham. "There was no sanctuary. There was no place really safe."

The device exploded at 10:22 a.m. The exact moment of the blast was marked Sunday with a wreath laying and tolling of the bells at the 16th Street Baptist Church.

The church was an organizing spot for civil rights demonstrations, and a dynamite bomb planted outside went off as Birmingham's public schools were being integrated for the first time. It had been the target of frequent bomb threats made by Klu Klux Klan members.

Attorney General Eric Holder and former Secretary of State Condoleezza Rice were among those in attendance, and both were scheduled to speak later in the day.

President Barack Obama issued a statement to mark the anniversary, saying the bombing "galvanized Americans all across the country to stand up for equality," and led to widespread support for the passage of Civil Rights Act of 1964.

Congregation members and visitors sang the old hymn "Love Lifted Me" and joined hands in prayer. The somber Sunday school lesson was followed by a raucous, packed worship service with gospel music and believers waving their hands.

"God spared me to live and tell just what happened on that day," said Rudolph, who testified against the Klansmen convicted years later in the bombing.

Rudolph was 12 at the time, and her family left the church after the bombing. She said it was important to return in memory of her sister, who was 14, and the three other girls who died: Carole Robertson and Cynthia Wesley Morris, both 14, and Denise McNair, 11.

Bombing survivor Sarah Collins Rudolph, who lost her right eye and sister Addie Mae Collins in the blast, stood by as members laid a wreath at the spot where the dynamite device was placed along an outside wall.

The Rev. Arthur Price taught the same Sunday school lesson that church members heard the morning of the bombing -- "A Love That Forgives." Then, the rusty old church bell was tolled four times as the girls' names were read.

A racially-mixed crowd of hundreds filled the pews of Alabama's 16th Street Baptist Church to mark the 50th anniversary of the church bombing by the Ku Klux Klan that killed four girls and became a landmark moment in the nation's civil rights struggle.

A hotbed of racism

The city of Birmingham, Alabama, was seen to be one of most segregated cities in the 1960s. Home to one of the most violent chapters of the Ku Klux Klan (KKK), its public officials often had alleged ties to the racist organization's members.

State governor at the time, George Wallace, was a fierce opponent of desegregation and fought hard against it. Meanwhile in the years leading up the attack, the city's police was under the control of Eugene "Bull" Connor - an ultra-segregationist, notorious for employing harsh tactics such as high-pressure fire hoses and police dogs against pro-civil rights demonstrators.

As the site of protests from both white supremacists and anti-racism activists, Birmingham played a major role in the development civil rights movement.

Martin Luther King Jr. was arrested in Birmingham in 1963 while leading supporters in a nonviolent campaign of demonstrations. From his prison cell, he penned "Letter from a Birmingham Jail," which justified his decision not to halt the demonstrations in the face of continued violence at the hands of local law enforcement officials. The letter, published in the national press, helped create widespread support for the civil rights cause.

The city of Birmingham, Alabama, a hotbed of racism in the 1960s, was one of most segregated cities at the time. Birmingham was home to one of the most violent chapters of the Ku Klux Klan (KKK) and its public officials often had ties to KKK members. Then Governor George Wallace was a fierce opponent of desegregation and fought hard against it. Perhaps the one incident he would become known for most was the infamous standoff in June 1954 between him and federal marshals during his attempts to block the entrance of two Black students from the University of Alabama. The symbolic move followed the Supreme Court decision in Brown v. Board of Education that struck down the separate but equal doctrine in public schools, holding that the education of black children in separate public schools from white students was unconstitutional. The city's police commissioner Eugene "Bull" Connor, was also an ultra-segregationist and had close ties to the KKK. He was notorious for his harsh tactics against Black demonstrators and their supporters, including the use of high-pressure fire hoses and police dogs. As a major hub for white supremacists and civil rights activists, Birmingham played a major role in the civil rights movement. Martin Luther King Jr. was arrested in Birmingham in the 1963 while leading supporters in a nonviolent campaign of demonstrations. From his prison cell, he penned a now famous "Letter from a Birmingham Jail" , which justified his decision not to halt the demonstrations in the face of continued violence at the hands of local law enforcement officials. The letter, published in the national press, helped create widespread support for the civil rights cause. The Birmingham Church Bombing The church served as a meeting place for the city's civil rights activists and they often organized campaigns on the steps of the church. the church received frequent bomb threats from KKK members. On the morning of the bombing, there were about 200 congregants attending services. The bomb exploded on the church's east side, causing its interior walls to cave in. Although most of the people inside were able to escape, four young girls- 14-year-old Addie Mae Collins, Cynthia Wesley and Carole Robertson and 11-year-old Denise McNair- were killed, their bodied found in a basement restroom. Ten year old Sarah Collins, who was also in the restroom, lost her right eye. More than 20 people were injured from the attack. The bombing’s aftermath The bombing was the third bombing in 11 days, all believed to be in response to a federal court order that had mandating the integration of Alabama's school system. Thousands of black protesters and their supporters gathered at the Church after the bombing to protest. Violence broke out across the city when Wallace sent police to break up the demonstrations. Two young African American men were killed during the clashes and many demonstrators were arrested. The National Guard was eventually called in to restore order and King later spoke before 8,000 outraged supporters who had gathered at the funeral for three of the victims. In 1977, Alabama Attorney General Bob Baxley reopened the investigation. The first of several tries saw the conviction of Klan leader Robert E. Chambliss, who was found guilty of murder. Three more Klan members, Bobby Frank Cherry and Thomas Blanton, would be brought to justice in the years followings. A fourth Klan member, Herman Frank Cash, died in 1994, before he could be tried. Although the perpetrators behind the bombing would not be brought to justice for more than a decade, the event marked a watershed moment in the civil rights movement. The fallout from the bombing and ensuing national outrage, built increased momentum for the civil rights cause and led to the eventual passage of the Civil Rights Act and the Voting Rights Act of 1965. Al Jazeera and the Associated Press

The city of Birmingham, Alabama, a hotbed of racism in the 1960s, was one of most segregated cities at the time. Birmingham was home to one of the most violent chapters of the Ku Klux Klan (KKK) and its public officials often had ties to KKK members. Then Governor George Wallace was a fierce opponent of desegregation and fought hard against it. Perhaps the one incident he would become known for most was the infamous standoff in June 1954 between him and federal marshals during his attempts to block the entrance of two Black students from the University of Alabama. The symbolic move followed the Supreme Court decision in Brown v. Board of Education that struck down the separate but equal doctrine in public schools, holding that the education of black children in separate public schools from white students was unconstitutional. The city's police commissioner Eugene "Bull" Connor, was also an ultra-segregationist and had close ties to the KKK. He was notorious for his harsh tactics against Black demonstrators and their supporters, including the use of high-pressure fire hoses and police dogs. As a major hub for white supremacists and civil rights activists, Birmingham played a major role in the civil rights movement. Martin Luther King Jr. was arrested in Birmingham in the 1963 while leading supporters in a nonviolent campaign of demonstrations. From his prison cell, he penned a now famous "Letter from a Birmingham Jail" , which justified his decision not to halt the demonstrations in the face of continued violence at the hands of local law enforcement officials. The letter, published in the national press, helped create widespread support for the civil rights cause. The Birmingham Church Bombing The church served as a meeting place for the city's civil rights activists and they often organized campaigns on the steps of the church. the church received frequent bomb threats from KKK members. On the morning of the bombing, there were about 200 congregants attending services. The bomb exploded on the church's east side, causing its interior walls to cave in. Although most of the people inside were able to escape, four young girls- 14-year-old Addie Mae Collins, Cynthia Wesley and Carole Robertson and 11-year-old Denise McNair- were killed, their bodied found in a basement restroom. Ten year old Sarah Collins, who was also in the restroom, lost her right eye. More than 20 people were injured from the attack. The bombing’s aftermath The bombing was the third bombing in 11 days, all believed to be in response to a federal court order that had mandating the integration of Alabama's school system. Thousands of black protesters and their supporters gathered at the Church after the bombing to protest. Violence broke out across the city when Wallace sent police to break up the demonstrations. Two young African American men were killed during the clashes and many demonstrators were arrested. The National Guard was eventually called in to restore order and King later spoke before 8,000 outraged supporters who had gathered at the funeral for three of the victims. In 1977, Alabama Attorney General Bob Baxley reopened the investigation. The first of several tries saw the conviction of Klan leader Robert E. Chambliss, who was found guilty of murder. Three more Klan members, Bobby Frank Cherry and Thomas Blanton, would be brought to justice in the years followings. A fourth Klan member, Herman Frank Cash, died in 1994, before he could be tried. Although the perpetrators behind the bombing would not be brought to justice for more than a decade, the event marked a watershed moment in the civil rights movement. The fallout from the bombing and ensuing national outrage, built increased momentum for the civil rights cause and led to the eventual passage of the Civil Rights Act and the Voting Rights Act of 1965. Al Jazeera and the Associated Press