DALLAS (AP) — Just minutes after President John F. Kennedy was fatally shot as his motorcade rolled through downtown Dallas, Associated Press reporter Peggy Simpson rushed to the scene and immediately attached herself to the police officers who had converged on the building from which a sniper’s bullets had been fired.

“I was sort of under their armpit,” Simpson said, noting that every time she was able to get any information from them, she would rush to a pay phone to call her editors, and then “go back to the cops.”

Simpson, now 84, is among the last surviving witnesses who are sharing their stories as the nation marks the 60th anniversary of the Nov. 22, 1963, assassination on Wednesday.

“A tangible link to the past is going to be lost when the last voices from that time period are gone,” said Stephen Fagin, curator at The Sixth Floor Museum at Dealey Plaza, which tells the story of the assassination from the Texas School Book Depository, where Lee Harvey Oswald’s sniper’s perch was found.

“So many of the voices that were here, even 10 years ago, to share their memories — law enforcement officials, reporters, eyewitnesses — so many of those folks have passed away,” he said.

Simpson, former U.S. Secret Service Agent Clint Hill and others are featured in “JFK: One Day in America,” a three-part series from National Geographic released this month that pairs their recollections with archival footage, some of which has been colorized for the first time. Director Ella Wright said that hearing from those who were there helps tell the “behind the scenes” story that augments archival footage.

“We wanted people to really understand what it felt like to be back there and to experience the emotional impact of those events,” Wright said.

People still flock to Dealey Plaza, which the presidential motorcade was passing through when Kennedy was killed.

“The assassination certainly defined a generation,” Fagin said. “For those people who lived through it and came of age in the 1960s, it represented a significant shift in American culture.”

On the day of the assassination, Simpson had originally been assigned to attend an evening fundraising dinner for Kennedy in Austin. With time on her hands before she needed to leave Dallas, she was sent to watch the presidential motorcade, but she wasn’t near Dealey Plaza.

Simpson had no idea that anything out of the ordinary had happened until she arrived at The Dallas Times Herald’s building where the AP’s office was located. Stepping off an elevator, she heard a newspaper receptionist say, “All we know is that the president has been shot,” and then heard the paper’s editor briefing the staff.

She raced to the AP office in time to watch over the bureau chief’s shoulder as he filed the news to the world, and then ran out to the Texas School Book Depository to track down more information.

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Later, at police headquarters, she said, she witnessed “just a wild, crazy chaotic, unfathomable scene.” Reporters had filled the hallways where an officer walked through with Lee Harvey Oswald ‘s rifle held aloft. The suspect’s mother and wife arrived, and at one point authorities held a news conference where Oswald was asked questions by reporters.

“I was just with a great mass of other reporters, just trying to find any bit of information,” she said.

Two days later, Simpson was covering Oswald’s transfer from police headquarters to the county jail, when nightclub owner Jack Ruby burst forth from a gaggle of news reporters and shot the suspect dead.

As police officers wrestled with Ruby on the floor, Simpson rushed to a nearby bank of phones “and started dictating everything I saw to the AP editors,” she said. In that moment, she was just thinking about getting out the news.

“As an AP reporter, you just go for the phone, you can’t process anything at that point,” she said.

Simpson said she must have heard the gunshot but she can’t remember it.

“Probably Ruby was 2 or 3 feet away from me but I didn’t know him, didn’t see him, didn’t see him come out from the crowd of reporters,” she said.

Simpson’s recollections are included in an oral history collection at the Sixth Floor Museum that now includes about 2,500 recordings, according to Fagin.

The museum curator said Simpson is “a terrific example of somebody who was just where the action was that weekend and got caught up in truly historic events while simply doing her job as a professional journalist.”

Fagin said oral histories are still being recorded. Many of the more recent ones have been with people who were children in the ’60s and remembered hearing about the assassination while at school.

“It’s a race against time really to try to capture these recollections,” Fagin said.