Juan Cole suggests that the March 15th deaths in Ishaqi, Iraq, were not the result of a deliberate massacre of civilians. As reported here, U.S. forces were after an al-Qaeda supporter alleged to be visiting town, and instead shot up a house full of (apparent) innocents:
...the long-range bullet wounds may indicate that they [U.S. troops] went in, guns blazing, before they realized who they were killing. At Haditha, it appears that Marines were just taking revenge on civilians for the killing that morning of one of their own. What is scarey at Ishaqi, if the story is borne out, is the cover-up.