MACON, Ga. (AP) — Nearly 50 years ago in a Birmingham church, five girls were getting ready for youth service when an explosion shattered the room they were in, killing four of them.

The surviving girl was trapped in the rubble, unable to move or see, screaming for her sister, who never responded. Later, a father identified the body of his 11-year-old daughter, who had worn her new dress to church that day and was last seen getting the sash tied.

Doug Jones befriended the father of Denise McNair, and about 40 years after the tragedy, Jones prosecuted two of the former Ku Klux Klansmen responsible for the bombing. Denise died in the blast alongside Carole Robertson, Addie Mae Collins and Cynthia Wesley.

As the 50th anniversary of the bombing approaches, Jones spoke Tuesday at Middle Georgia State College in Macon, at times choking back tears as he recounted both his experiences and the church bombing that “truly sent shock waves throughout the world,” he said.

Jones, a Birmingham native and former U.S. Attorney, was 9 years old when the 16th Street Baptist Church was bombed Sept. 15, 1963. He remembers hearing about the incident, but he did not fully understand the impact until years later.

As a second-year law student, Jones skipped class to witness the trial of the first man convicted of the bombing. He remembers the day of closing arguments — it would have been Denise McNair’s 26th birthday.

Jones never dreamed that 24 years later, he would be delivering the closing argument against another former Klansman — on what would have been Robertson’s 51st birthday.

After witnessing that trial and befriending Denise McNair’s father, “I had a piece of it that I carried with me,” Jones said after Tuesday’s presentation.

The bombing case was reopened a year before Jones became U.S. attorney in 1997, and “a series of pieces of puzzles” came together, placing Jones at the helm of a team that prosecuted former Klansmen Thomas Blanton Jr. and Bobby Frank Cherry in 2001 and 2002, respectively.

Perhaps the biggest job for Jones was putting his own puzzle together. He dug through records, photographs, video footage and conducted interviews to determine why the church was targeted. He showed video of an incident in 1957, when the Rev. Fred Shuttlesworth tried to enroll his children in an all-white Birmingham school, inciting protests from a mob of people. A video shows Shuttlesworth being dragged into the street, beaten and kicked. A man, later identified as Cherry, reached into his back pocket and grabbed a pair of brass knuckles.

Shuttlesworth invited Martin Luther King Jr. to march in Birmingham, where a majority of the marchers were children. Jones showed photos of firefighters spraying black children with powerful water hoses and police officers unleashing dogs on the children. About 2,000 teenagers clustered inside Birmingham jails after the marches, and many of those children met at 16th Street Baptist Church, Jones said.

After devoting five years to the two cases, Jones clinched the convictions. Both men were sentenced to life in prison; Cherry died in prison, and Blanton is still serving. Neither showed any remorse, Jones said.

But, for Jones, the trials “emotionally drained” him, he said.

Jones compared winning the cases to a Super Bowl victory. But working with the families and reliving the horror of that day — and that time period in the South — was heart wrenching, Jones said, especially when he was not sure what the outcome would be.

“You could probably hear my voice crack a couple times in there,” he said, “and that’s 10 years after the fact.”

One of his biggest worries was that the jury would view the case simply as part of history. Jones set out to show that “it was about families who had lost loved ones, families who had never gotten justice,” he said.

He worked with one witness who came from a nursing home to testify, despite having just suffered a stroke. Another witness testified with medical staff and equipment on standby after having a heart attack and being admitted to the Intensive Care Unit before the trial.

Jones questioned one woman who heard about her sister’s death on the radio. The mother of one girl was upstairs in another part of the church when the bomb exploded. She remembers screaming, “My baby, my baby,” Jones said.

Denise McNair’s father recalled the hours after the blast. When he identified his only daughter’s body, she still had a piece of mortar embedded in her skull. But Jones’ most powerful witness was Sarah Collins Rudolph, the only survivor of the five girls in the church classroom, he said.

Rudolph, who is still blind in one eye, remembers the last time she saw her sister, Addie Mae Collins. The girls were excited about the upcoming youth service and were complimenting Denise’s new dress. Sarah caught a glimpse of her sister tying Denise’s sash, and then everything went dark. Jones saved Rudolph as his last witness.

“It was a remarkable ending to a remarkable story,” he said.