MOBILE, Alabama – Alastair Stevenson is thankful he was able to finish the Boston Marathon in the time he did.

Had he not, the tragic circumstances unfolding in downtown Boston might have personally affected him.

"My wife, Melanie, was sitting in the same exact spot (where the explosion occurred) for five hours," Stevenson, cross country coach for both the men's and women's teams at the University of Mobile, said today. "She got up and left when I finished the race. Had I run slower, it might have been a different ball game."

Stevenson, 37, ran and completed his first Boston Marathon, leaving the scene once his race was over so he could get a shower. He and his wife were returning to the finish line area when two blasts went off killing two people and reportedly injuring at least 28.

Stevenson, who has coached the University of Mobile Rams' cross country teams for four years, said everyone in his group is accounted for.

"Everyone that came up (to Boston) from Mobile avoided injury in the two explosions," he said. "We're definitely grateful for that."

Boston Marathon Explosion Causes Confusion, Multiple Injuries and Death on April 15, 2013 46 Gallery: Boston Marathon Explosion Causes Confusion, Multiple Injuries and Death on April 15, 2013

After the explosion, he said, "The first thing in my mind was 'are there going to be any others?' My thought was to get as far away from there as possible."

Part of that fear was the smell from the smoke billowing in the air, he said.

"There was a sulfur smell," Stevenson said. "Then, it was crazy from there. The emergency vehicles were coming and going and closing everything off and evacuating the area. People were crying in the streets. It was a pretty disturbing situation."

He and his wife cannot return to their hotel as it's located near Copley Square, site of the chaos that ensued at the marathon's finish line. He's confident that he will be able to return this evening.

"All that area is under heavy restrictions," Stevenson said. "I was very scared at the time, but I'm OK now. I wasn't worried about not getting back to the hotel ... I thought there might be more detonations going off."

While there is no confirmation yet on whether the blasts were the result of a terrorist attack, Stevenson said something he saw before the race was unusual.

"At the starting line this morning, they had bomb sniffing dogs and the bomb squad out there," he said. "They kept announcing to runners not to be alarmed, that they were running a training exercise."

He added, "I've run a lot of races like this one, but I never saw bomb dogs at the starting line of any running event. It led me to believe that something like (a bomb detonation) might have happened."