Here is another account of this, this time from Associated Press:

Residents gave new details Monday about the shootings of civilians in a western Iraqi town, where the U.S. military is investigating allegations of potential misconduct by American troops last November.

The residents said troops entered homes and shot and killed 15 members of two families, including a 3-year-old girl, after a roadside bomb killed a U.S. Marine.

The military, which announced Friday that a dozen Marines are under investigation for possible war crimes in the Nov. 19 incident, said in a statement Monday that a videotape of the aftermath of the shootings in Haditha, 140 miles northwest of Baghdad, was presented in support of the allegations...

And it goes on with more information about what survivors say happened, and on where the military authorities are now saying.