Article Photos: Oklahoma City Memorial Marathon officials will be smart, but they do not want to give into fear 43/44

Medical workers aid injured people at the 2013 Boston Marathon following an explosion in Boston, Monday, April 15, 2013. Two explosions shattered the euphoria of 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. (AP Photo/The Boston Globe, David L Ryan)  MANDATORY CREDIT ORG XMIT: MABOD807