People react as an explosion goes off near the finish line of the 2013 Boston Marathon in Boston, Monday. Two explosions went off at the Boston Marathon finish line on Monday, sending authorities out on the course to carry off the injured while the stragglers were rerouted away from the smoking site of the blasts.

Medical workers aid injured people at the 2013 Boston Marathon following an explosion in Boston.

Bud Wisseman was a few miles from the Boston Marathon's finish line.

His race had begun like so many before.

Eating pasta for dinner. Lacing up a pair of Nike running shoes.

But this time -- at his 24th consecutive Boston Marathon -- things changed, the 74-year-old runner said.

Police cars flew by.

"I crossed the 25-mile marker at Fenway Park. I had just a mile to go at the finish line, and there were runners in the road," Wisseman said while in a Boston hotel Monday afternoon. "The road was totally filled up. They were walking back. They were saying the finish line was closed."

"I walked up a little bit and asked a policeman. He said there had been an explosion," Wisseman said.

Three people were killed and more than 100 injured in two explosions near the finish line of the prestigious, 26.2-mile-long race that 23,000 runners had to qualify for to run. Chaos unfolded after the blasts.

Wisseman was hoping to set a personal record next year by running 25 consecutive marathons in the prestigious road race. Only 48 other people have done so. He hasn't missed a day of running since Feb. 18, 1988.

"Whether or not they're going to give me credit, I don't know. That doesn't fit in the scheme of importance right now," he said. He estimates he would have finished at about five hours and eight minutes this year.

In Chattanooga, 14 area residents were registered to run.

Alan Outlaw, who recently became co-owner of Fast Break, 19 Cherokee Blvd., had registered and planned to run the race. He was at the running specialty store on Monday afternoon.

Outlaw's wife phoned him after the news broke.

"Wasn't that a blessing?" Outlaw recalls her saying.

The Chattanooga Track Club, which has about 600 members including Outlaw, issued a statement late Monday.

"We at the Chattanooga Track Club are very shocked and saddened by the horrific events today at the Boston Marathon. A day that is supposed to be about celebrating the great accomplishments and hard work of thousands of runners has turned into a day of tragedy. Our thoughts and prayers are with the victims and their families. We also express concern for our Chattanooga runners and we hope that they are all safe and that they can return home safely."

With other major marathon events coming up, it's unclear how security will be handled or if Monday's tragedy will deter people from running the race.

"I guess it's just life anyway. You either do it or you don't," Outlaw said. "I think a marathon is something; for a lot of people, it's a once-in-a-lifetime kind of thing. It's something that we do, that we live and breathe every day."

Outlaw said his thoughts and prayers are with those who were killed or injured. He said that just after the four-hour mark of the race, the runners who would be running through would tend to be older. Blood stained the pavement, and there were reports of people with severed limbs.

U.S. Sen. Saxby Chambliss, R-Ga., vice chairman of the U.S. Senate Select Committee on Intelligence, issued the following statement, "My prayers go out to the people of Boston, and especially to those who were killed or injured in today's attack. As the evidence mounts that this was a terrorist attack, our intelligence and law enforcement agencies must do whatever is necessary to find and interrogate those responsible so we can prevent similar attacks."

Many people used social media to connect to loved ones after the explosion to let them know they were fine. Cell phone service was shut down shortly after the explosions to prevent remote detonation of any other explosive devices.

"Hey everyone. Just wanted to let you know that I am fine. I was out of the area when the bombs went off," said Ryan Shrum, of East Ridge, on Facebook Monday afternoon. Shrum finished the race at two hours and 57 minutes.

Wisseman's wife, Sonia, normally cheers for him at the 25.5-mile marker. When he went to look for her, the area was vacant.

Wisseman stopped three people as he made his way back to the hotel trying to call her. He couldn't get through. They were reunited at the hotel.

"Fortunately, she wasn't there [near the explosion,]" he said.

The Associated Press contributed to this story.