In his living room in a flat, neighborly suburb north of the city, Pete Hargraves poises on the edge of an armchair and fiddles with the bandages on his hands. For weeks he has asked himself the same question: Was there anything else he could have done to save the lives of three American peace envoys to Bosnia?

Anyone who knows Pete Hargraves will tell you he's a courageous man. Ask his wife. Ask his colleagues in the Diplomatic Security Service. Ask the agent he risked his life to rescue from a firefight in Somalia.

No one doubts his bravery this time, either, or that of Army Lt. Col. Daniel Gerstein, the other American survivor of a freak accident that killed three Americans and one French soldier in an armored personnel carrier that plunged off a crumbling mountain road as it made its way to Sarajevo last month. Assistant Secretary of State Richard Holbrooke, who'd been traveling in the same convoy, immediately called Hargraves "a genuine hero." The Army praised Gerstein's bravery, too, and gave him a Soldier's Medal.

But the accident, as senseless to most Americans as the ceaseless violence shredding the entire Balkan region, has lingered with Hargraves. As the security officer for the American Embassy compound and personnel in Sarajevo, he was responsible for the safety of the Americans, and he is haunted by his inability to help.

"Pete exemplifies the old medieval

idea of a virtuous person," says Rosa Trainham, his former supervisor here, who relied on him heavily in the complicated passport fraud cases the office investigates. "He is motivated from the heart. I believe he does these things because he has to. He looks like an average guy in an average house, but to me, he's extraordinary."

A SWAT team police officer in a town outside Dallas for more than eight years, Hargraves, 39, describes himself as "not uncomfortable with danger." When he put in for the Sarajevo job last year, he knew the situation could be perilous, but it appealed to him personally and professionally. Diplomacy can't function if the diplomats aren't secure, and it would be his job to maintain the security of a new embassy in a war zone.

"It was a challenge I couldn't turn down," he says. City of Danger Hargraves had always set himself high goals, and after seven months in Sarajevo, he could point to concrete accomplishments: improving the blast protection of the embassy and chancery. Reinforcing screening mechanisms. The creation of a local guard force on the perimeter of the compound.

He had arrived in a world of nightly strafing and shelling. The airport was eventually closed, and there were limits on fuel and water in a city where each was in short supply. Security was often heightened in sudden alerts. "When Captain O'Grady was shot down, Serbs realized the Americans were involved, and we became a higher target," Hargraves says, referring to Scott O'Grady, the pilot who hid from the Serbs until his dramatic rescue.

The Saturday morning of the accident, the sky was overcast, but, unlike the previous week, there was no rain. Before dawn, Hargraves and three French soldiers set off to meet the peace envoys at a helicopter landing site about four hours away. Expecting the envoys earlier that week, they had traveled the mostly dirt roads of the mountain route. They were in disrepair but passable.

By mid-morning, when Holbrooke, Lt. Gen. Wesley Clark of the Joint Chiefs of Staff and the rest of their party landed, the sun had burned through the fog. Accompanied by U.S. military, the two senior officials got into the first car. Hargraves and the French soldiers climbed into the second, a French armored personnel carrier (APC), accompanying Deputy Assistant Secretary of State Robert C. Frasure, President Clinton's special envoy to the former Yugoslavia; Joseph J. Kruzel, deputy assistant secretary of defense for European and NATO affairs; Air Force Col. Samuel Nelson Drew, a National Security Council aide; and Gerstein.

Two soldiers sat in front; the third guarded the rear doors. Hargraves and the envoys faced each other on seats on either side of the vehicle. At first the trip was quiet. At one point, Hargraves opened a window and showed the visitors how to look out if they wanted to. "Nobody did," he says. "I think they were concentrating on their upcoming meetings.

About 45 minutes into the journey, the APC stopped on the outside curve of the mountain road. Hargraves still doesn't know why. But earlier, he'd noticed members of the U.N. rapid reaction force higher up on the mountain improving the surface of the rain-soaked road in order to bring in weaponry.

When the vehicle started to move, Hargraves knew something was wrong. Suddenly, the dirt road underneath the two outside wheels crumbled, the vehicle tilted outward and, like a giant rolling pin, began its fatal spin. Over and over and over, increasing speed as it went, the vehicle plunged down the 500-meter hill. Stunned observers estimated from 20 to 50 rotations before it came to a stop.

After the first roll, Hargraves figured out what was happening. "It seemed like an eternity," he says. "It's always very slow in life-threatening situations. . . . I didn't think we'd go on for as long as we did," he says.

As Hargraves replays the incident, his eyes wander off somewhere beyond the family Rottweiler scratching at the back door and the trampoline in the yard, somewhere into the mangled Bosnian countryside. His voice gets progressively softer. He hesitates, and apologizes. "I've healed a lot physically," he says. "But I haven't done a lot of this." A Helluva Punch'

As the vehicle hurtled downhill, Hargraves saw that the back doors were open and the French soldier who had been next to them was gone. Suddenly he found himself crushed against the doors and seconds later half-outside them looking back at the APC. "I knew I had to get in or out," he says.

When he couldn't find a way to push himself all the way out he grabbed one of the seats, pulled it to his face for protection, and somehow lodged his back into the wall behind him, hoping to ride it out. (Gerstein would later describe the same general survival tactics: pushing his face to the side of the vehicle to protect it, and jamming his feet and back to brace himself in a similar manner.)

"It's funny what you think about," says Hargraves. "When I was a young man, I did a little bit of boxing. And I remember getting hit with punches you never saw and how it stuns you. At one point I hit my face against the vehicle, and it was the same thing. Wow,' I thought, that was a helluva punch.' "

When the vehicle came to a stop on its side on a flat part of the mountain, Hargraves pushed against the jammed doors. He caught sight of a small open hatch above him. As he hoisted himself through, he saw Gerstein, who helped him out. Wounded but alive, they stumbled away.

After about 10 steps, Hargraves collapsed and realized two things: His back was on fire. And there were still people in the vehicle.

The front of the APC had already exploded in flames. Returning to the burning vehicle as ammunition began to ignite, Hargraves and Gerstein helped pull Kruzel out.

They went back again. Looking inside, Hargraves didn't see any other survivors. In agony, he and Gerstein retreated just when a third explosion engulfed the vehicle. "There wasn't anything else I could do," says Hargraves softly.

Alert enough to rip from his vest the two medical kits he was carrying as a precaution and throw them to the Bosnians who rushed to help, Hargraves soon began weaving in and out of consciousness. "Maybe I passed out from pain -- or maybe I chose to block out what had happened," he says remorsefully. "And the magnitude of it all. . . . I felt responsible for everybody there."

The loss of Frasure, Drew and Kruzel, who died later of his injuries, was devastating. "I don't think I'll ever answer the question why four men survived and four didn't," says Hargraves. "You can go to church and ask for answers, but I don't think you'll ever get one." Bad News

Sunday morning, Cathy Hargraves was awakened by a 6:30 phone call from Washington. "There's been an incident," said the official. "Pete is alive. We don't know the extent of the injuries."

She was used to her husband's dangerous jobs. He'd done them often -- even sought them out -- and emerged okay. But she'd always worried that one day bad news would come with a knock on the door or a phone call.

A few hours later a second phone call gave her details. Pete was in an American military hospital in Ramstein, Germany. Friends rallied to look after Nicholas, 14, and Kelly, 13, and by 4:45, she was on her way there.

The next day, when officials brought her to her husband, she didn't recognize him. French doctors in Sarajevo had sewn up facial wounds, but no one had cleaned him up.

And when Hargraves saw his wife, he burst into tears. "I couldn't save them," he told her.

"He was very upset," says Cathy Hargraves. " I lost three men,' he told me. I couldn't get them out.'

"That's been the hardest part for him," she says.

A little more than three weeks later, that's what's still hard. After medical attention for his broken nose and arm, many broken ribs, cracked vertebrae and numerous burns, bruises and cuts -- first by a French unit in Bosnia, then in Germany and here in the States -- his physical progress has been remarkable. Letters of praise, including one from President Clinton a few days after the incident, have helped his spirits, but only so far. "The physical healing has been my major concern," says Hargraves. "I haven't even started to deal with the emotional issues."

Last week Hargraves asked to be released from his Sarajevo assignment. He'd considered returning. "I've got a very strong work ethic," he explains. But his recovery is taking longer than he had hoped. And he realizes the embassy needs someone in place immediately. (Gerstein, who had fewer and less serious injuries, has already returned to duty.)

The inactivity imposed by Hargraves' recuperation makes some days frustrating for him. Caught in a lengthy line at the post office, unable to go back to work and still aching from his injuries, he felt powerless, frustrated, angry. He grumbled, "What a way to live."

And then he realized what he was saying, and that against all odds, he was alive. He chided himself, "You think this is a bad day? There's no such thing as a bad day anymore." CAPTION: Pete Hargraves's physical recovery has been remarkable, but, he says, "I haven't even started to deal with the emotional issues" of the accident in Bosnia. CAPTION: The Hargraves family in Texas, from left: Nicholas, Cathy, Pete and Kelly.'