... and how some skated free:

The 1965 investigation by the Federal Bureau of Investigation determined the bombing had been committed by four known KKK members and segregationists: Thomas Edwin Blanton Jr., Herman Frank Cash, Robert Edward Chambliss, and Bobby Frank Cherry.[6] However, it was not until 1977 that the first suspect, Robert Chambliss, was prosecuted by Attorney General of Alabama William "Bill" Baxley and convicted of the first degree murder of one of the victims, 11-year-old Carol Denise McNair.

As part of an effort by state and federal prosecutors to reopen and try cold cases involving murder and domestic terrorism from the civil rights era, the state of Alabama placed both Blanton Jr. and Cherry on trial, who were each convicted of four counts of first degree murder and sentenced to life imprisonment in 2001 and 2002, respectively. Future United States Senator Doug Jones successfully prosecuted Blanton and Cherry.[7] Herman Cash died in 1994, and was never charged with his alleged involvement in the bombing.

19 sticks of dynamite (some say)

In the early morning of Sunday, September 15, 1963, several members of the United Klans of America—Thomas Edwin Blanton Jr., Robert Edward Chambliss, Bobby Frank Cherry, and, allegedly, Herman Frank Cash[18]—planted a minimum of 15 sticks[19] of dynamite with a time delay under the steps of the church, close to the basement. At approximately 10:22 a.m., an anonymous man phoned the 16th Street Baptist Church. The call was answered by the acting Sunday School secretary, a 15-year-old girl named Carolyn Maull.[20] The anonymous caller simply said the words, "Three minutes"[21]: 10  to Maull before terminating the call. Less than one minute later, the bomb exploded. Five children were in the basement at the time of the explosion,[22] in a restroom close to the stairwell, changing into choir robes[23] in preparation for a sermon entitled "A Rock That Will Not Roll".[24] According to one survivor, the explosion shook the entire building and propelled the girls' bodies through the air "like rag dolls".[25]

The explosion blew a hole measuring seven feet (2.1 m) in diameter in the church's rear wall,[26] and a crater five feet (1.5 m) wide and two feet (0.61 m) deep in the ladies' basement lounge, destroying the rear steps to the church and blowing a passing motorist out of his car.[27] Several other cars parked near the site of the blast were destroyed, and windows of properties located more than two blocks from the church were also damaged. All but one of the church's stained-glass windows were destroyed in the explosion. The sole stained-glass window largely undamaged in the explosion depicted Christ leading a group of young children.[14]

Hundreds of individuals, some of them lightly wounded, converged on the church to search the debris for survivors as police erected barricades around the church and several outraged men scuffled with police. An estimated 2,000 black people converged on the scene in the hours following the explosion. The church's pastor, the Reverend John Cross Jr., attempted to placate the crowd by loudly reciting the 23rd Psalm through a bullhorn.[28]
Casualties

Four girls—Addie Mae Collins (age 14, born April 18, 1949), Carol Denise McNair (age 11, born November 17, 1951), Carole Rosamond Robertson (age 14, born April 24, 1949), and Cynthia Dionne Wesley (age 14, born April 30, 1949)—were killed in the attack.[29] The explosion was so intense that one of the girls' bodies was decapitated and so badly mutilated that her body could be identified only through her clothing and a ring.[30] Another victim was killed by a piece of mortar embedded in her skull.[31] The pastor of the church, the Reverend John Cross, recollected in 2001 that the girls' bodies were found "stacked on top of each other, clung together".[32] All four girls were pronounced dead on arrival at the Hillman Emergency Clinic.[33]

Between 14 and 22 additional people were injured in the explosion,[34][35] one of whom was Addie Mae's younger sister, 12-year-old Sarah Collins.[36] She had 21 pieces of glass embedded in her face and was blinded in one eye.[37] In her later recollections of the bombing, Collins would recall that in the moments immediately before the explosion, she had watched her sister, Addie, tying her dress sash.[38] Another sister of Addie Mae Collins, 16-year-old Junie Collins, would later recall that shortly before the explosion, she had been sitting in the basement of the church reading the Bible and had observed Addie Mae Collins tying the dress sash of Carol Denise McNair before she returned upstairs to the ground floor of the church.[39]

https://en.wikipedia.org/wiki/16th_Street_Baptist_Church_bombing