It was an act of "pure, pure concentrated evil", Charleston's mayor said - a black community's leading lights extinguished at the hands of a young white man, who was welcomed into their Bible study session.
In one blow, the gunman ripped out part of South Carolina's civic heart.
A state senator who doubled as the church's minister, three other pastors, a regional library manager, a high school coach and speech therapist, a government administrator, a college enrolment counsellor and a recent college graduate.
Six women and three men who felt called to open their church to all.
Dylann Storm Roof, 21, had complained that "blacks were taking over the world" and that "someone needed to do something about it for the white race", according to a friend who alerted the FBI.
US President Barack Obama called the tragedy yet another example of damage wreaked on America by guns.
Head of the National Association for the Advancement of Colored People, Cornell William Brooks, said "there is no greater coward than a criminal who enters a house of God and slaughters innocent people".
Others bemoaned the loss to a church that has served as a bastion of black power for 200 years, despite efforts by white supremacists to wipe it out.
"Of all cities, in Charleston, to have a horrible hateful person go into the church and kill people there to pray and worship with each other is something that is beyond any comprehension and is not explained," said Mayor Joseph Riley Jr.
Spilling blood inside "Mother Emanuel", founded in 1816, evoked painful memories across the United States, a reminder that black churches so often have been the targets of racist violence.
US Attorney General Loretta Lynch said the attack would be investigated as a hate crime.
Meanwhile, Obama, who personally knew the lead pastor Clementa Pinckney, was one of the few politicians to call for stricter gun control.
"I've had to make statements like this too many times," the President said.
"At some point, we as a country will have to reckon with the fact that this type of mass violence does not happen in other advanced countries."
The chain of events
The mass shooting set off an intense 14-hour manhunt that ended when 21-year-old Dylann Roof was arrested in a traffic stop in a small North Carolina town, 220 miles (350 km) north of Charleston, South Carolina, where the shooting occurred, officials said.
Roof, whose social media profile suggests a fascination with white supremacy, waived his right to extradition and was flown back to South Carolina hours after his arrest.
Wednesday's gun violence at the nearly 200-year-old Emanuel African Methodist Episcopal Church caps a year of turmoil and protests over race relations, law enforcement and criminal justice in the United States. A series of police killings of unarmed black men has sparked a renewed civil rights movement under the "Black Lives Matter" banner.
An undated handout photo provided by the Berkeley County South Carolina Government on 18 June 2015 shows 21 year-old Dylann Roof (EPA/BERKELEY COUNTY) Source: BERKELEY COUNTY
Four pastors, including Democratic state Senator Clementa Pinckney, 41, were among the six women and three men shot dead at the church nicknamed "Mother Emanuel," which was burned to the ground in the late 1820s after a slave revolt led by one of its founders and was later rebuilt.
"Once again, innocent people were killed in part because someone who wanted to inflict harm had no trouble getting their hands on a gun."
"The fact that this took place in a black church obviously raises questions about a dark part of our history," said US President Barack Obama. "Once again, innocent people were killed in part because someone who wanted to inflict harm had no trouble getting their hands on a gun."
Watch: Obama calls for gun control in wake of Charleston shooting
The United States has seen a series of mass shootings in recent years, including the 2012 massacre at Sandy Hook Elementary School, where a gunman killed 20 children and six adults. Democratic efforts to reform the nation's gun laws failed after that incident.
Gift of a gun
A man who identified himself as Carson Cowles, Roof's uncle, told Reuters that Roof's father had recently given him a .45-caliber handgun as a birthday present and that Roof had seemed adrift.
"I don't have any words for it," Cowles, 56, said in a telephone interview. "Nobody in my family had seen anything like this coming."
Roof was armed with a handgun when confronted by police but surrendered peacefully as he was taken into custody, said Charleston Police Chief Greg Mullen.
In a Facebook profile apparently belonging to Roof, a portrait showed him wearing a jacket emblazoned with the flags of apartheid-era South Africa and of the former Rhodesia, now Zimbabwe, both formerly ruled by white minorities. Many of his Facebook friends were black.
People are seen here hugging at the memorial site of the Emanuel African Methodist Episcopal (AME) Church where nine people were murdered in Charleston, South Carolina, USA, 18 June 2015. (EPA/JOHN TAGGART) Source: EPA
Roof was arrested on two separate occasions at a shopping mall earlier this year for a drug offense and trespassing, according to court documents.
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Roof's mother, Amy, declined to comment when reached by phone.
"We will be doing no interviews, ever," she said before hanging up.
Police said the church shooting unfolded about an hour after Roof joined a small Bible-study group in the church, welcomed apparently as the only white participant, and suddenly opened fire on the victims as they sat together.
Sylvia Johnson, a cousin of Pinckney, told MSNBC that a survivor told her the gunman reloaded five times during the attack despite pleas for him to stop.
"He just said, 'I have to do it. You rape our women and you're taking over our country," Johnson said.
US Attorney General Loretta Lynch said her office was investigating whether to charge Roof with a hate crime motivated by racial or other prejudice.
Under federal and some state laws, such crimes typically carry harsher penalties. But South Carolina, which has the death penalty, is one of just five US states lacking hate crime laws.
Rising racial tensions
Demonstrations have rocked New York, Baltimore, Ferguson in Missouri and other US cities following police killings of unarmed black men including Eric Garner, Freddie Gray and Michael Brown.
A white police officer was charged with murder after he shot Walter Scott, an unarmed black man, in the back in April in neighboring North Charleston.
The Southern Poverty Law Center, which researches US hate groups, said the attack illustrates the dangers that home-grown extremists pose.
"Since 9/11, our country has been fixated on the threat of Jihadi terrorism. But the horrific tragedy at the Emanuel AME reminds us that the threat of homegrown domestic terrorism is very real," the group said in a statement, referring to the Sept. 11, 2001 attacks on the United States.
There have been 4,120 reported hate crimes across the United States, including 56 murders, since 2003, the center said.
"It is a very, very sad day in South Carolina"
Other victims included three church pastors: DePayne Middleton Doctor, 49, Sharonda Coleman Singleton, 45 and Reverend Daniel Simmons, 74; Cynthia Hurd, a 54-year-old employee of the Charleston County Public Library, and Susie Jackson, 87; Ethel Lance, 70, Tywanza Sanders, 26, and Myra Thompson 59, an associate pastor at the church, according to the county coroner.
"This is going to put a lot of concern to every black church when guys have to worry about getting shot in the church," said Tamika Brown, who attended one of several overflow prayer vigils held at Charleston churches.
Police in Charleston responded to multiple bomb threats around the city through the course of the day on Thursday.
Parishioners applaud during a memorial service at Morris Brown AME Church for the people killed Wednesday during a prayer meeting inside a historic black church in Charleston, S.C., Thursday, June 18, 2015. (AAP) Source: AAP
Three people survived the attack.
"It is a very, very sad day in South Carolina," Governor Nikki Haley, a Republican, in a tearful statement.
That grief rang hollow for some civil-rights activists, who noted that the state capital in Columbia still flies the Confederate flag, the rallying symbol of the pro-slavery South during the Civil War.
"The reality that racism is alive and well and that we have a problem with guns," said Clayborne Carson, founding director of the Martin Luther King Jr. Research and Education Institute at Stanford University. "People will throw up their hands and say 'how terrible' and the governor of South Carolina will put the Confederate flag of the state at half staff and then will get back to passing more laws that allow people to carry guns."
