WASHINGTON (AP) _ Just before he apparently killed himself, Adm. Jeremy M. Boorda, the Navy's top officer, abruptly left his Pentagon office troubled by questions he was to face that day about the legitimacy of one of his Vietnam combat decorations.

Boorda, 57, the widely admired chief of naval operations since April 1994, died Thursday of what police preliminarily were treating as a self-inflicted gunshot wound to the chest.

Initial forensic evidence ``indicates this case will be classified as a suicide,'' a Metropolitan Police Department statement said.

Boorda's body was found about 2:05 p.m. in a side yard next to his quarters at the Washington Navy Yard. People nearby heard the gunshot and rushed to his aid. He was pronounced dead at D.C. General Hospital a few minutes later. Police said a .38 caliber handgun and a suicide note were recovered near the body.

Two suicide notes were found, officials said, although the notes were sealed by police, and the contents were not disclosed.

The Washington Post reported in today's editions that the notes, one of which was written to Boorda's wife, expressed concern about the disgrace resulting from an impending disclosure questioning whether he had earned two Vietnam-era decorations he had once worn.

The New York Times said the notes suggested Boorda had been driven to take his life by fear that the reputation of the Navy, already battered by a series of scandals, would be further harmed by the disclosures about his medals.

Boorda was to have met about the time of the shooting with the Washington bureau chief of Newsweek magazine, which was working on a story concerning his medals.

Administration officials, speaking on condition of anonymity, said there was no evidence the shooting was accidental and no suspicion of foul play.

Boorda's top deputy, Adm. Jay L. Johnson, took over as acting Navy chief after the shooting.

Colleagues and lawmakers who had spoken with Boorda in recent days expressed shock and dismay.

At the White House, President Clinton praised Boorda, the first enlisted sailor in the history of the Navy to rise to its top position, as a man of ``extraordinary energy, dedication and good humor.''

Navy Secretary John Dalton, the service's civilian chief, said he had met with Boorda a day earlier. ``He was in great spirits,'' Dalton told a news conference.

The questions about the legitimacy of Boorda's combat ``V'' award came at a time when the Navy as an institution has come under fire from critics for moral lapses, starting with the 1991 Tailhook sexual assault scandal and more recently focusing on drug use at the Naval Academy and sexual harassment in the officer corps.

In recent interviews Boorda had emphasized his determination to move the Navy into a new era and away from the controversies that dogged it in recent years.

Rear Adm. Kendell Pease, who was with Boorda a little over an hour before the shooting, said Boorda was to have met with the Newsweek journalist in his Pentagon office at 2:30 p.m. to discuss questions about his Vietnam combat medals.

The implication was that Newsweek was investigating whether Boorda for years had worn a combat ``V'' decoration that he was not authorized to wear.

Pease said that when he told Boorda about 12:30 p.m. what the subject of the interview was, the admiral abruptly announced he was going home for lunch instead of eating the meal that had been brought to his office.

``Admiral Boorda was obviously concerned,'' Pease said. Pease declined to characterize Boorda as distraught.

He said Boorda had asked him how they should handle the Newsweek questions, then without waiting for a reply had answered his own question: ``We'll just tell him the truth.''

In a statement, Newsweek Editor Maynard Parker said the magazine ``had not reached any conclusions'' about the medals.

Pease said he learned after Boorda's death that the admiral had become aware about a year ago that someone was looking into his Vietnam medal awards. Pease said he had no indication of how Boorda had reacted except that the admiral had stopped wearing a combat ``V'' on his Vietnam campaign medals.

Boorda was awarded commendation and meritorious service awards for his duty in Vietnam, which included combat operations. But copies of the citations released Thursday by the Navy did not mention that Boorda qualified for wearing a combat ``V.''

Navy regulations say the citation must specifically authorize the ``V,'' and that is solely for individuals who are exposed to personal hazard due to direct hostile actions. Pease said he did not know the details of Boorda's awards.

Boorda was known as a gregarious, hard-working admiral.

Defense Secretary William Perry called him ``a sailor's sailor. At every stage of his career, he put the interests of sailors and their families first.''

As Navy chief, Boorda was a member of the Joint Chiefs of Staff, whose chairman, Gen. John Shalikashvili, said Thursday, ``The Navy has lost a great Captain.''

Clinton praised Boorda for his work in Bosnia and for showing ``unwavering concern for the men and women'' of the U.S. military.

Stunned lawmakers took to the Senate floor to praise Boorda and express their grief.

Sen. Ted Stevens, R-Alaska, chairman of the Senate Appropriations defense subcommittee, said he was ``in a state of shock.'' He called Boorda ``one of the bright stars'' of the Navy.

As commander of NATO forces in southern Europe, Boorda was in charge of a NATO air strike against four Bosnian Serb aircraft flying in violation of the U.N. ban on fixed-wing flights.

Clinton appointed Boorda as chief of naval operations, the Navy's top job, in 1994 after Adm. Frank Kelso II resigned. His first mission: to try to restore the service's reputation following the Tailhook sexual assault scandal involving Navy aviators at a Las Vegas hotel.

The grandson of Ukrainian Jewish immigrants, Boorda was born in South Bend, Ind., and grew up in Chicago. He dropped out of high school, fibbed about his age and joined the Navy at the age of 17.

He and his wife, Bettie, have four children.