Nearly 11 years ago, thousands of U.S. troops launched the bloodiest battle of the Iraq War. The fight for the western city of Fallujah ultimately killed 82 of the estimated 12,000 Americans who were there, and wounded 600 more. The insurgents fared much worse than that: According to U.S. military estimates, some 2,000 insurgents were killed, and another 1,200 were captured.

By many accounts, some of those insurgent corpses remained in the streets of Fallujah for weeks, growing more grotesque by the day. And for the last year, they have been at the center of a military investigation first launched in January 2014, after TMZ published photographs depicting Marines burning corpses. U.S. military officials said at the time that they were investigating what happened, but no additional details were released.

E-mails released through the Freedom of Information Act and published on the military blog Task & Purpose late Monday provide new perspective into what may have occurred. A Marine who was there at the time told public affairs officials that commanders ordered the bodies to be burned because U.S. troops were living in close proximity to them and the corpses were “literally exploding” from becoming bloated in the sun.

“You could literally taste the corpses the smell was atrocious and I can still remember it to this day,” the Fallujah veteran said in an e-mail published by Task & Purpose.

The Fallujah veteran added that the Marines were in firefights too often to properly bury the bodies, and also faced wild dogs who ate the corpses and attacked the troops. The Marines were told to get rid of the dead bodies so there were no food sources, he said.

Contacted separately, another Fallujah veteran said that “anyone on the lines knows the smell is sickening and lowers morale,”and that Red Crescent, a humanitarian organization, “refused to pick up some bodies that were badly decomposed.

“What else can you do?” the Marine asked.

The investigation was launched by Marine Corps Forces Central Command (MARCENT) while Lt. Gen. Robert B. Neller was its commander. He has since been nominated to become the service’s next commandant, and awaits confirmation from the Senate. Documents from the investigation have not been released.

The Marine Corps closed its investigation in June 2014, concurring with the investigating officer’s findings that the burning of the remains did not violate any orders, rules of engagement or conventions, said Maj. Christian Devine, a service spokesman. No charges were brought against anyone. Neller served as the consolidated disposition authority for the cases, overseeing them, and closed the investigation afterward, Devine said.

A Marine official, speaking anonymously in order to discuss the case candidly, said that the investigation found that the decomposition of many of the remains indicated they were in the area before the Marines launched Operation Phantom Fury in November 2004. Nearly all civilians had evacuated the city by that point, leaving no civilians to remove and bury the dead.

Marine commanders also were concerned about disease being transmitted to U.S. troops through the remains. There were about 200 cases of service members getting sick or developing infections at the time.

“This action was taken for purely hygienic and public health reasons, and there was never an intent to treat any remains in a disrespectful manner,” the Marine official said.

The explanation may not satisfy everyone. Army Col. Steve Warren, a Pentagon spokesman, told TMZ when the photographs were published last year that the actions depicted appeared to violate the Uniform Code of Military Justice. While some of the images show Marines dousing the corpses in gasoline and burning them, others depict them posing with the bodies.

One of the Fallujah veterans contacted by Marine Corps headquarters expressed disgust to a Marine Corps headquarters official when he learned that the photographs had been published nearly a decade later.

“The pictures aren’t telling the full story and it is sad that this was put out on a gossip site 10 years after the fact just to stir controversy from irresponsible reporters and whomever is the idiot who leaked this to TMZ,” the Marine said in the e-mail released to Task & Purpose. “If there is anything I can do to assist you in the damage control please let me know.”

This post has been updated to include comments from Marine Corps headquarters.