Check out how the attack happened..who usually are the ones who win the Marathon..they come from Africa, Uganda, Congo, South Africa and other countries, they are usually the ones that win..the rest are just average folk running for the heck of it or for some charity they are raising money for..the attack did not occur til AFTER the winners had already made it through..whoever did this wanted to make sure that Americans were the ones injured or killed
Or they messed up and pressed the wrong speed dial number...