– The customer needed a radiator for a minivan and the job gave Terry Butler an excuse to get away from the shop’s TV, which was blaring live news about planes smashing into the World Trade Center and leaving the Pentagon smoldering.

“I like to keep busy,” Butler said. “Because I knew what was going on, I didn’t want to believe it.”

No one did on that day, 15 years ago Sunday.

Butler, a burly yet soft-spoken man, willingly serves as a witness to the world events that flew over his head on Sept. 11, 2001, and crashed at 10:03 a.m. in the rural Somerset County community, about 80 miles southeast of Pittsburgh.

“This story has to be told,” Butler said, his voice cracking with emotion. “That’s my job, that’s what I feel I need to do.”

If you traveled to the Flight 93 Memorial’s 15th anniversary events this weekend, you may have run into Butler and heard his story in person. He is one of numerous local residents who volunteer their time helping National Park Service rangers keep alive an interlocking story of terrorism, heroism and small-town pride that speaks of the briefness of human life and the importance of American history.

“It changed me to appreciate life and what it means,” Butler said.

Here’s why:

Moving away from the TV, Butler got back to work, tracking down a 1995 Dodge Caravan in Stoystown Auto Wreckers’ 50 acres of junk vehicles. Under the hood, prying off the radiator, he heard engines roar somewhere above.

He turned to the left. Nothing. He turned the other way and there it was.

“It was a plane,” Butler said.

He would learn later it was United Airlines Flight 93. But on this cloudless day all Butler knew was the airliner seemed too close to the trees and Allegheny Mountain hills that rise and fall around Stonycreek Township, the borough of Shanksville and various unincorporated villages off the beaten path of the ­Pennsylvania Turnpike.

“I just watched,” he said.

The plane pulled up. Then just as fast, it banked sharply right and disappeared behind trees.

“I saw the mushroom cloud, and heard explosion after explosion,” he said.

As Butler radioed for his disbelieving co-workers to call 911, a concussive force reverberated through Shanksville-Stonycreek School District’s one and only building, which serves preschoolers through high-schoolers.

In a fourth-grade classroom, Ben Eisler watched the shock wave rumble across the drop ceiling. Now 24 and a volunteer firefighter, Eisler said the image is seared in his memory. “I don’t think anyone can forget.”

Jet crashed going 563 mph

That sentiment is echoed across the country, especially on the anniversary of the attacks. But here, it’s more personal. The site, sound and feel of the hijacked Boeing 757 smashing into a vacant strip mine at 563 mph reverberate in this community. And so does the knowledge that the passengers and crew died fighting their captives, as messages relayed in phone calls and the plane’s data recorders show.

“We got the call around 10:06 a.m. that morning to respond to an aircraft down,” said Terry Shaffer, the now retired chief of the Shanksville Volunteer Fire. Co. “At the time we knew what was going on in New York City but we never expected to have something like this in our area.”

All 33 passengers, seven crew members and four hijackers died. No one on the ground did. Residents here know the difference between life and death was measured in heartbeats that day.

“It’s a very tragic thing but if it had to happen, if it was going to happen, it happened in such a great place,” Shaffer said. “A few seconds longer, it surely would have hit our town or the high school.”

That knowledge — captured soon after the crash in an aerial photo of students and teachers holding hands to spell “Thank You” toward the heavens — is why so many residents here have embraced their unfortunate celebrity not as a curse but as a blessing.

Often not seen in pictures are stories of residents who manned the crash site in two-hour volunteer shifts to ensure it was respected and not vandalized. Using notebooks to keep track of the facts, they relayed to tourists and mourners alike how the hole smoldered and the crash left little wreckage above ground except scattered papers and pieces of engine and fabric. They even graciously guided a multitude of curious motorists to a place that instantly became a tourist attraction.

“We were just neighbors and friends,” said longtime volunteer Chuck Wagner, 67, of Stonycreek Township.

They helped bring to fruition the Flight 93 National Memorial, which grew from hay barrels and a chain-link fence holding small mementos into a stunning feat of architecture that embraces the beauty of nature and the resolve of mankind. Many of these residents are helping the National Park Service mark the 15th anniversary of the terrorist attacks at a service Sunday morning at the memorial.

“We came a long way in 15 years with the memorial,” Butler, the eyewitness, said. “I hope we keep it going.”

Former Gov. Tom Ridge remains in awe of the community’s effort in embracing its part of history.

“From the day that plane went down to today and, I think, evermore, they have been the volunteer security team, the volunteer docents,” Ridge said. “I don’t think any story about the memorial should exclude a warm, grateful embrace of the people of Shanksville and that region, who for years and years have treated it as a sacred ground that it’s proven to be.”

The Flight 93 Memorial, now accessible from a new road off Route 30 instead of the winding path through Shanksville, has attracted thousands of visitors each weekend since it officially opened last year.

“It’s dramatic in its configuration because it actually tells a story,” said Ridge, who shortly after the attacks resigned as governor to lead the newly created Homeland Security Office under President George W. Bush.

Inside the Visitor Center Complex a wall-size displays use images, text, sound and video to bring Sept. 11, 2001, back to life. One display replays newsreels of the New York and Washington attacks.

“Oh my God another plane has just hit another building,” a news anchor reports.

Another display plays the last recorded moments of Flight 93’s passengers as they used Airfones and cellphones to call 911 and loved ones.

“Honey, are you there?” Lauren Catuzzi Grandcolas’ preserved voice says to her husband, Jack. “Wake up sweetie. OK, I just wanted to tell you I loved you.”

Other displays tell of investigators’ search for clues in the strip mine and surrounding woods that retired State Police Capt. Frank Monaco said yielded little because the plane hit the soft ground so fast the bulk of it burrowed underground.

“It was surprising to me because you never would have known there was a plane crash,” Monaco said. “It just looked like a flaming hole with smoke coming out.”

The site was ringed by firefighters, EMTs and state troopers, who rushed to the scene expecting to recover bodies or save lives but found neither. They were left in states of sympathy, anger and ­confusion, Ridge said.

Today, the crash site resembles a park.

The outside of the memorial features towering walls on either side of a walkway that follows the final path of the doomed flight that was forced off its Newark-to-San Francisco course. The walkway ends on a coal-black platform that overlooks the crash site, which has been given new life as a field of grasses, trees and wildflowers. A path cuts through the wildflowers to a plaza adorned with benches and stone panels dedicated to each of the crew and passengers who died.

“It’s peaceful, somber, impressive,” retired Marine Major Mick DuBois, 66, of Marshalltown, Iowa, said on a visit last week.

‘These brave people’

One day a tower of wind chimes will rise at the site, adding a perpetual voice to the mountain winds that on a September morning scattered paper and debris for miles.

“I can’t believe it’s been 15 years,” said Toni Holmes, 59, of Commerce Township, Mich. “It’s like it was yesterday and to see this site brings back all the memories of these brave people.”

Exactly what they did will never be known, but it’s clear they, including Bloomington native Tom Burnett Jr., began fighting back at 9:57 a.m. and kept the hijackers from reaching their target — believed to be either the White House or Capitol, both about 20 minutes flight time from Shanksville.

“They took the first step against terrorism,” Butler said, “And we can never forget that.”