Rebel coalition group claims 2 Americans -- including Douglas McCain -- die in Syria . Only one has been named ; both were fighting with extremist militant groups in Syria . U.S. official : " The two men died as a result of an explosion that occurred during the fight against ISIS militants near Raqqa, Syria." Obama spokesman : U.S.-born extremists dangerous due to training , willingness to die .
Rebel coalition group claims 2 Americans -- including Douglas McCain -- die in Syria . Only one has been named ; both were fighting with extremist militant groups in Syria . U.S. official : Foreigners fighting for such extremist groups come from 50 nations . Obama spokesman : U.S.-born extremists dangerous due to training , willingness to die .