Washington ? The Army’s top doctor became the latest casualty in the flap over shoddy treatment of wounded troops at Walter Reed Army Medical Center.

Lt. Gen. Kevin Kiley, the Army’s surgeon general who had been accused of callous indifference by troops and their families, resigned Sunday, but military sources said he was told to put in his papers.

“I submitted my retirement because I think it is in the best interest of the Army,” Kiley said Monday in a statement. He said the troops back from Iraq and Afghanistan deserve the nation’s best and “I was blessed to walk among them.”

“Leaders must be held accountable for what happens under their command,” acting Army Secretary Pete Geren said of Kiley, whose ouster followed quickly on the sacking of Army Secretary Francis Harvey and Maj. Gen. George Weightman, the former Walter Reed commander.

Geren named Maj. Gen. Gale Pollock, a chief nurse, to replace Kiley temporarily.

Geren said the disclosures that Walter Reed outpatients were living in roach-infested rooms “have tarnished the reputations of us all,” but he said the bureaucracy of the military health care system was the bigger problem.

The disability system of the military and the Veterans Administration “has become a maze that is overly bureaucratic and in some cases unresponsive and needlessly complex,” Geren said.

As Geren dwelled on the failures at Walter Reed, four patients at the Army’s flagship hospital touted some of its successes Monday.

Homeland Security Secretary Michael Chertoff presided as four wounded soldiers back from Iraq – two born in Mexico, one from Portugal and one from Haiti – were sworn in as U.S. citizens.

One of them, Army Pfc. Dwishnicka Randolph, 26, who came as a child from Haiti to Brooklyn, said, “I felt I did the right thing to become part of this beautiful country.”

Randolph said she was diagnosed with a rare form of facial cancer in Iraq and, despite the problems at Reed, “I have gotten outstanding treatment. I went from being terminal to I’m going to be OK.”