Marathon organizers worldwide, are re-evaluating safety standards, and how to keep runners and spectators safe.
Runners began training months ago, that's around the same time security plans went into place.
Oklahoma City organizers have been putting the finishing touches on the Memorial Marathon. A race that commemorates one of the deadliest terrorist’s attacks America has seen.
"Since the bombing of the Murrah Building we take that very seriously," said a Memorial Marathon organizer.
Oklahoma City officials stood by, watching the Boston Marathon, and then the explosions happened.
"We prepare for what could be a worst case scenario," said a Memorial Marathon organizer.
Race officials had already added security for the Memorial Marathon, because the number of runners has increased. They also had already planned for bomb techs to be scattered throughout the crowd.
"It’s a close knit industry. We meet several times a year," said Chris Liberman, Executive Director of the Williams Route 66 Marathon.
Liberman said across the country, race organizers are constantly tweaking security.
"People went immediately into action, because they had a plan," said Lieberman.
Perhaps, more alarming, many organizers consider the Boston Marathon to be the safest.
"This event in Boston occurred at a marathon and we're less than two weeks away from a similar race by our standards," said Liberman.
A race, and yet another tragedy to remind everyone that planning can only go so far. Lieberman said there will be another meeting in June to discuss improvement plans.