While the world stopped to tune in to the terror in Boston on Monday afternoon, the pandemonium at the marathon’s finish line hit closer to home for one Williston man.

Mark Amondson, 30, has lived and trained as a runner in Williston for the last three years. Four years ago standing in line for dinner before the same race, Amondson began chatting about running with a fellow marathoner – his now girlfriend who joined him to run again Monday.

Sitting in their hotel room with a coach after they finished, Amondson said he heard the successive booms.

“I knew immediately it was a bomb,” he said on the phone Tuesday morning from Boston’s Logan Airport. “It was loud. It was much louder than a gunshot. It wouldn’t have been a cannon from the start of the race.”

“And about 15 seconds later, another one hit,” he said, adding that the hotel where they were staying was less than a mile from the race’s end.

Amondson, an elite runner, was the first to finish from North Dakota about an hour and a half before the first explosion. He placed 280th, with a time of 2:40.29. His girlfriend, Alexis Nees of Michigan, finished about 30 minutes before the afternoon blasts.

“Big explosion right below our hotel. We heard two,” Amondson posted on Facebook afterward. “Please be praying.”

Officials in Boston were investigating the two explosions at the finish line Tuesday, which reportedly left at least three people dead and 140 injured, some with amputated limbs.

“I just looked down below onto the street, and there were people running frantically,” Amondson said. “I could see the whole thing happen. All the way up until we went to bed there were probably 100 emergency vehicles around the area.”

At the same time, Amondson said they knew a friend was in the area but were not able to reach her for another hour because of overloaded phone service. They eventually discovered she was safe, finishing 90 seconds before the explosions.

“She was stuck down there and that was our main concern because we could not get a hold of her,” he said. “I’m sure it was like 9/11 where everyone’s trying to call.”

Amondson said he could not see smoke from the room and saw no one with injuries, but watched as people ran from the area.

“Just people looking panicked,” he said, adding that the he was moving from the window to the street to watch.

Neil Amondson, Mark’s father who moved to Williston with his son about three years ago from Washington state, said he was at Anytime Fitness following the results with a friend.

They heard news of the explosions and Neil said moments passed until he heard that his son was OK.

Marathon Monday is also Patriot’s Day in Massachusetts, a holiday and one of the most celebrated days in the city every year. Neil said he has traveled to Boston and cannot believe the tragedy.

“This is just so bizarre,” he said. “Of all things, you never thought something like this would happen. The Boston Marathon is the most prestigious marathon race in the world. It’s the most sought-after race. It’s hard just to qualify for.”

Neil said his son runs 60 to 80 miles per week and trains on Williston’s “Halliburton Hill” and in Spring Lake Park, he said. Mark Amondson said he runs outside in Williston throughout the year – as long as the temperature is above zero degrees.

“It’s just so foreign to think that this would happen,” Neil said. “It’s really tragic to see what’s unfolding on TV. Just really hard to imagine what it would be like.”

While Nees is a radiologist at the University of Michigan, Mark Amondson works at Williston’s Public Works Department. Mark Amondson said he always enjoys running in Boston and this was his third year.

“It’s just legendary,” he said of the race. “It’s incredible to see how everyone in the community comes out to support you and just the support you get from other runners and the community is beyond words.”

Mark Amondson said Monday’s terror will not stop him from returning to Boston.

“Most likely I’ll come back next year,” he said. “It could happen anywhere.”

Mark Amondson said Tuesday morning on the way to the airport, some fellow runners said they “didn’t feel right about wearing their medals.”

“It’s pretty somber here at the airport,” he said, adding that discounts were being offered at Logan because of the events.

Mark Amondson said he feels as if he’s dealing with the tragedy, but called it “surreal.”

“It was like watching 9/11 on TV but then looking at the finish line and knowing I was there an hour before right in that same area,” he said, adding that he saw people who had lost limbs on TV. “It really came to life, and we saw the severity of it.”

Overall, Mark Amondson said he is thinking about the people most affected.

“Just keeping people in my prayers that were affected and the family members that were affected,” he said.

“I was very impressed with how so many people just immediately dove in to help,” he added. “People didn’t run away from it, they ran toward it to help others.”