The Clint Eastwood movie 15:17 to Paris, in theaters Friday, is about a thwarted terror attack on an Amsterdam-to-Paris train in August 2015. It has special resonance for a Lehigh Valley family — they were aboard when the incident occurred.

The Sewells of Bethlehem, Pa., were on the last leg of a European summer vacation when a terrorist with multiple guns and several hundred rounds of ammo left a bathroom and shot a passenger, intending to inflict mass casualties. The attack was stopped almost immediately by the extraordinary actions of  two vacationing American servicemen (Spencer Stone and Alek Skarlatos) and their buddy Anthony Sadler — the subjects and stars of Eastwood’s new movie.

Mark Sewell, traveling with his wife, Kathy, and three daughters, was five cars away. They didn't see or hear what was happening. All they knew was that the train had stopped. Minutes later, announcements in French informed passengers that there had been a terrorist incident.

The passengers were hustled off the train — Sewell saw wounded men (Stone, the attacker, and a passenger were hurt) and blood on the ground  as he was steered into a nearby building. His daughters didn't want to look, and Sewell didn't want them to look.

"The bulk of the efforts of my wife and I at that time was to manage the emotions of the kids," said Sewell, a Villanova grad — Kathy attended Temple — who moved from Devon to Bethlehem 20 years ago.

In the chaos following their disembarkation, Susie happened to see John Browne, who was wearing a Lehigh Valley Hooligans T-shirt, and introduced her family to Browne and his wife, Cori. Despite the trying circumstances, they still found a connection to home.

Some hours later, still waiting for updates and instructions in a local gymnasium, train staff asked if the passengers needed anything.

Sewell asked for a beer. That got a laugh from the nervous crowd, and the employees were happy to help: "They were very accommodating."

The family arrived in Paris 12 hours later than scheduled, By the next morning, full details of the incident had been reported, and  they knew that three Americans helped save their lives. Mark and Kathy marched to the American embassy to find a way to formally thank the men, but it was closed.

Sewell's daughter Susie crafted a comprehensive blog post describing the incident and thanking the men, and then, several weeks ago, Mark saw television ads for the movie, which stars the "ordinary" men who saved their lives.

Again, he reached out to Warner Bros. hoping to find a way to reach them. In the process, the studio arranged a screening, which brought the reality of the event back to Sewell.

"I think every one of us had a tear in our eye at the end when it showed how much ammunition the guy had. Something like 300 rounds." he said.

The screening also allowed the Sewells to see in detail for the first time what happened when the terrorist started shooting five cars away.

"When you see how it unfolded, it really sinks in — just how differently things could have turned out if these guys hadn't been there," Sewell said.

He also had time to think about the strange twists of fate involved — the Sewells were visiting Ireland, Belgium, and France, and chose to take the train only at the last minute, after deciding that a rental car procured in Amsterdam was too cramped.

It makes him feel even more lucky and even more grateful.

"I still want to say on behalf of my family how indebted I am to those guys," Sewell said. "They saved not only my life but the lives of my whole family."

Susie, in her blog post, put it this way: "Because of those men I got to finish college (again). Because of those men I got a chance to move out of my parents' house, get a job and experience life living on my own … Because of those men, that couple that we met on the train had a chance to create a beautiful baby girl. Because of those men my sisters got to flourish in their own careers … Because of them. I am blessed to be alive and I truly experience each day differently."

The Sewells also got to enjoy the Eagles' Super Bowl win, which most of the family watched in Philadelphia Sunday evening, and stuck around for the festivities.

This trip, however, they drove.