The White House says it took nearly a month for President George W. Bush to be told that the military was investigating reports that Marines murdered unarmed civilians in Iraq. Bush aides had said this week that the president was briefed "soon after" the investigation was opened. A Time magazine reporter first asked US military officials on Feb. 10 of circumstances surrounding the alleged massacre on Nov. 19, in which 24 people in Haditha, an insurgent stronghold in western Iraq, were killed after a bomb attack on a military convoy in which a Marine died. Four days later, on Feb. 14, Lt. Gen. Peter Chiarelli, commander of Multinational Corps Iraq, ordered an investigation, White House press secretary Tony Snow said Thursday. But, Snow said, Bush was not informed about the investigation until March 11, when he was briefed by national security adviser Stephen Hadley. Bush pledged Thursday that the Pentagon will "get to the bottom of this," and results of the inquiry will be made public.