BOSTON (WZZM) -- A Grand Rapids runner and his wife are safe following two explosions at the Boston Marathon finish line Monday afternoon.

Troy Noll finished the race around 1 p.m. and did not witness the pandemonium, but he says the majority of runners would have been finishing the race closer to the time of the explosions.

"You would expect the volume of runners crossing the finish line to peak between 1:30 and 2 o'clock," said Noll.

Troy finished 1,437th out of an estimated 27,000 runners and was on his way back to his hotel with his wife when the bombs went off.

Earlier in the day, Brianne Noll was cheering along the sidelines. She says the race track would have been full of people around the time of the explosion.

"Around the four-hour mark there would have been a lot of people watching runners," said Brianne.

Even before the explosion, Brianne said the finish line was packed with people. "It was quite chaotic on the finish line-- it was wall-to-wall people from the barriers to the storefronts and the sidewalk area. There was no more room than just standing room."

Troy says security was tight early Monday morning before the race began. "I was at the Athlete's Village, 26 miles away and even in a rural community, I could see they had police or military personnel on the rooftops of the middle school or high school where the runners were staging," said Troy. "There were definitely several local-area police divisions present at the start all the way to the finish line on the course. Then at the finish line, there were just dozens and dozens of police lining the street in the last couple miles of the race to keep crowds back."

Troy says the race was immediately canceled after the explosions and the course was blocked off.

Authorities say two bombs detonated around 2:50 p.m., killing at least two people and injuring 49. Police found another two explosive devices along the race track and safely detonated them.