It happened a half lifetime ago in Birmingham, Alabama: It, too, was a racist attack that used a bomb -- not a gun as in Charleston -- against the 16th Street Baptist Church, killing four black girls on a Sunday in 1963.
"The emotional impact, whether you're talking about the black community or the white community, is it happened in a church, in a place that is out of bounds," the Birmingham church's current pastor, Arthur Price Jr., said of the two attacks.
"This is not supposed to be a target because this is a place where you come to believe in Jesus and behave like Jesus," Price added. "But in a church, it's shocking, just like mass murder in a school is shocking."
The legacy and lessons from the 1963 Birmingham bombing are being resurrected as the nation fathoms how a 21-year-old white man allegedly sought to start a race war by killing a pastor and eight congregants during a Bible study inside a landmark black church.
Survivors and relatives of '63 bomb
Lisa McNair's sister Denise was one of four girls killed in the Birmingham bombing.
"I just was overwhelmed," McNair told CNN affiliate WBRC about hearing of the Charleston massacre. "I just laid in bed for awhile because it was too much to take. It's so sad for me, sad that we're still doing this to each other 50 years after Denise was killed.
"But we're human beings," McNair added. "And human beings are sinful and flawed and all we can do is continue to pray to God."
A survivor of the 1963 explosion condemned the "ugly history of the burning, bombing, banning and belittling of black churches in America."
"The shooting at the Emanuel AME Church
and the death of nine people were frighteningly reminiscent of the bombing in 1963. The common thread of both of these events is hatred," the Rev. Dr. Carolyn McKinstry, former president of the Sixteenth Street Foundation Inc., wrote in Time magazine.
"Yes, many things have changed since 1963. The tangible signs of segregation were removed. But the real question is: Have hearts changed?" McKinstry wrote.
Invocation of MLK
President Barack Obama sealed a connection between the two events separated by 52 years when he cited how the Rev. Martin Luther King Jr. eulogized the 1963 victims. King's words became became one of the era's memorable speeches.
Whereas King spoke of the girls' deaths as "martyred heroines of a holy crusade for freedom and human dignity," Obama urged greater gun control when he recited a portion of King's eulogy:
"They (the victims) say to each of us, black and white alike, that we must substitute courage for caution," King said. "They say to us that we must be concerned not merely with who murdered them but about the system, the way of life, the philosophy which produced the murders. Their death says to us that we must work passionately and unrelentingly for the realization of the American Dream."
14 years vs 14 hours
Perhaps one of the most dramatic differences between Birmingham and Charleston is how the wheels of justices churned slowly in one and move swiftly in the other, said Doug Jones, a former U.S. attorney in Alabama who led the prosecution against two of the defendants in the 1963 bombing.
In the 1963 bombing, three former Ku Klux Klan members were convicted of murder, but the first conviction came 14 years after the crime, in 1977.
The next two convictions came in 2001 and 2002 -- almost 40 years after the explosions. Jones, an appointee during President Bill Clinton's second term, was the lead trial prosecutor in those two cases.
In the Charleston attack, suspect Dylann Roof
was arrested 14 hours after the crime. He has confessed to the killings, law enforcement officials said. Of course, the legal process has just begun.
The contrast of 14 years versus 14 hours isn't lost on Jones, now a private attorney who's lived all but one of his 61 years in Birmingham.
"At the end of the day, the wheels of justice moved slowly, but they still moved and there was still justice. People say justice delayed is justice denied, but that doesn't have to be the case," Jones said.
"Fortunately, here we have this person in custody" in the Charleston case, Jones added. "So those wheels of justice are going to move in a much swifter way than what we experienced in Birmingham."
Justice will salve the open wounds in Charleston, but Jones added: "You won't get away from the scars, but it will help heal the community."
A fourth suspect in the Birmingham bombing died in 1994 without ever being charged.
On the streets of Charleston
Charleston native Jerry Goodwin, 54, attended elementary school across the street from the desecrated church, whose nickname has long been "Mother Emanuel" because its roots go back to 1791 and to a coalition of free blacks and slaves. The church was formally founded in 1816.
Goodwin and his wife, Bridgette, found both church assaults senseless.
"I think it stems from the same act of hatred, racism. It's just a different generation," said Jerry Goodwin, who traveled from his Charlotte, North Carolina, home to visit his mother in Charleston. "A church is a symbol of refuge. This is a place you can always come to if there's turmoil in your community."
The Rev. Dr. William Swinton Jr., pastor of Ebenezer AME Church in Charleston
, noted how the church is a spiritual and symbolic center of the black community.
"To attack the church is to really hit us at our core. And that's what makes this so painful, particularly for our community," Swinton said. "For AMEs in this community, Mother Emmanuel is our mother."
Dearrick DeSaussure, 58, a special education teacher, remembered attending Mother Emanuel as a child with his grandmother.
"This is history, son," his grandmother told him then. "This is the first black (AME) church in the South."
Gunfire inside a house of worship left DeSaussure stunned.
"This is the last place that you expect something like this," he said. "This is where any foundation of any community starts."
Slaughtering innocents and supplicants at prayer led artists and pundits alike to express anguish over social media.
"Sickening," tweeted novelist John Green. "Over 50 years since the Birmingham church bombing, and here we are."
, a political analyst, wrote in Cosmopolitan magazine that "racialized terror should never again be considered a relic of the past."
Charleston is the new generation's millstone, Maxwell said.
"The Charleston church massacre is our Birmingham," Maxwell tweeted.
'Where can you be black?'
Equating the two atrocities more than a half century apart inevitably renews a national discussion about race.
"If you can't be black in the church, where can you be black in this country any more," said Bakari Sellers, a former South Carolina legislator and a friend of slain Pastor Rev. Clementa Pinckney.
"This is one of the oldest churches in the South. This is not just any church. This reminds us of Birmingham. It reminds us of the poor little girls ...," Sellers added.
For now, the U.S. Justice Department has opened a hate crime investigation into the South Carolina attack partly because Roof, who was arrested Thursday, allegedly stood up inside the church and told worshippers that he was there "to shoot black people," according to a law enforcement official.
Houses of worship ought to provide sacred shelter for the faithful. When the profane world crashes in, it becomes an obscenity that leaves many speechless.
"It is something that's so unfathomable that it's understandable you can't formulate a question," said the Rev. Craig Robinson, pastor of Bethel African Methodist Episcopal Church in Bay Shore, New York. "When you think about the many instances, even within this last year, of violence against black bodies and black institutions, it's heart wrenching, and it's truly unthinkable."
A time to eradicate racism
Many call this week's violence outright terror.
"It was an act of terror -- that's how every black person (and people of other races) I know describes the massacre. We feel angry and terrorized and ashamed of our nation," Roxanne Jones, a founding editor of ESPN Magazine and former vice president at ESPN, wrote in an opinion for CNN.
Though two generations have passed since Birmingham, racism endures in America. But some see this week's violence as a moment of opportunity as well as grief.
"We must also understand that it shows the problem does extend to the new generation," said Harry R. Jackson, Jr. senior pastor of Hope Christian Church in Washington, D.C. "If a 21-year-old can have this kind of vitriol, this is an endemic national problem.
"This is an opportunity for us to eradicate racism, as we understand it on our watch, and if we don't take this moment, we're going to see a lot of the fabric of the American community absolutely split apart," he added.
An irrepressible institution
The South Carolina church has a history of resurrection.
In 1822, the church was burned to the ground after plans for a slave revolt were revealed.
The church, however, rose again after the congregation rebuilt it and adopted the name "Emanuel," meaning "God with us."
As for Birmingham's church, it thrives and even holds one-hour tours about its history for $5.
This week's tours were sold out, the pastor said. Visitors must schedule one in advance.