The commandant of the Marine Corps has traveled to Iraq with an explicit warning for his troops to guard against what he calls "the risk of becoming indifferent to the loss of human life," as senior Pentagon officials are bracing for an investigation into the killing of 24 Iraqis last November in the town of Haditha.
The officials told ABC News the investigation will likely result in criminal charges that could range from dereliction of duty to murder. Investigators say six of those killed were children ranging in age from 2 to 11.
A videotape shot by an Iraqi journalism student showed the bloody aftermath. One man said, "A whole family was wiped out … they were innocent people."
As this unfolds, military officials said they feared Haditha would come to mean what My Lai -- the site of a massacre of Vietnamese civilians by American troops in 1968 -- had come to mean for an earlier generation.
The incident is still under investigation, but several senior military officials say at least seven Marines could face criminal charges.
Although the investigation is not complete, the Pentagon has already briefed key members of Congress on the details of the investigation. After a briefing on Thursday, Senate Armed Services Committee Chairman John Warner told reporters, "There are established facts that incidents of a very serious nature did take place."
ABC News has been told by several senior military officials that investigators have so far established the following:
-- Early in the morning of Nov. 19, a roadside bomb hit a small convoy of 12 Marines, killing Marine Lance Cpl. Lance Terrazas. All the Marines belonged to Kilo Company of the 3rd Battalion 1st Marine Regiment.
-- Shortly after the bomb went off, the Marines saw a taxi approaching and fired, killing five Iraqi men. Military officials say all the Iraqis turned out to be unarmed.
-- Some of the Marines, including a sergeant, then entered a cluster of nearby homes from where, they later claimed, they had taken enemy fire. Military officials now say they believe there was no enemy fire and that the killings were unprovoked. By the time they left, six civilians had been killed, including a 3-year-old boy.
-- In a second incident, officials said, a squad led by a sergeant went into the town of Hamandiyah to apprehend a suspected insurgent. When they didn't find him, they allegedly dragged an innocent man out of a house, shot him and then planted an AK-47 on his body to make him look like an insurgent.
By the time the dust settled, at least 24 Iraqi civilians, most unarmed, lay dead.
Sources familiar with the investigation say some of the Marines have confessed, and that seven Marines and a sailor have been removed from Iraq in connection with this incident and placed in custody at Camp Pendleton, Calif.
An official told ABC News: "There was no logic in what they did. They just wanted to kill somebody."
ABC News has learned from sources close to the investigation that the ranking Marine in the group who entered the homes and is a focus of the investigation is 25-year-old Sgt. Frank Wuterich.
The military issued a press release on Nov. 19 saying a roadside bomb killed one Marine and 15 civilians, and that an additional eight insurgents were killed in a firefight. It was not until February -- when Time magazine showed a U.S. military spokesperson a videotape of the bloody aftermath taken by a Iraqi journalism student -- that the military investigated the incident.
Sources familiar with the investigation say another group of Marines who came on the scene shortly after the killings took photographs of the dead Iraqis. Those photos were seized by military criminal investigators just before those Marines finished their tour of duty in Iraq in early April. Sources familiar with the photos say they show people shot at close range.
Already two senior officers higher up the chain of command -- Capt. Luke McConnell, Kilo Company commander, and Lt. Col. Jeffrey Chessani, Battalion commander -- have been relieved of their duties due to "loss of confidence" by their commanders. Neither McConnell nor Chessani were on the scene at the time of the killings. A third Marine commander, India Company's Capt. James Kimber was also relieved of his duties for an unrelated incident.
In a sign of how serious the Pentagon takes this, the Marine Corps' top officer, Gen. Michael Hagee, is traveling to Iraq to offer a stern reminder to fellow Marines. The Marines have distributed a copy of the speech Hagee plans to give.
"We do not employ force just for the sake of employing force," Hagee says in the speech. "We use lethal force only when justified, proportional and, most importantly, lawful."
In light of these two incidents, the Pentagon is now bracing for two separate trials this summer featuring Marines accused of killing innocent Iraqi civilians. Officials say they are determined to show the allegations are taken seriously, and that anyone found guilty will be dealt with severely.