Pentagon Room 1D457 was a Navy shop.

It was on the first "deck" -- the first floor -- of the building's southwest face. It was filled with grizzled sea dogs and smart computer geeks, former ship drivers and ex-chopper pilots; weather experts, photographers and a gifted Navy illustrator.

With its fresh renovations, the room felt as crisp and bright as a brand new frigate. The dozens of military and civilian employees of the Navy Command Center had moved there in just the past month.

There were smart kids just starting out, some in their twenties; people who were "short," or soon to retire; and ex-salts from the Cold War and 'Nam who'd already seen some stuff.

Shortly after 9:30 a.m. on Tuesday, Rick Sandelli, 48, a former helicopter pilot who worked for a Navy anti-drug task force in the room, ambled over to a gimpy wall clock. The darned thing was stuck again, but if you tapped on the glass you could get it going.

As Sandelli was about to reach for the clock, it was a normal, pleasant morning on board Pentagon 1D457. Outside, though, a hijacked 100-ton airliner was hurtling toward them, about to change everything.

In the terrorist attack Tuesday on the Pentagon that is believed to have killed 124 people who worked in the building, Room 1D457, on the first floor of the building's D Ring, one of the outermost, was among the hardest hit.

Twenty-six of the Navy's 42 active-duty and civilian personnel listed as missing or dead worked in the sprawling, cream-colored room, according to the Navy and interviews with those who escaped or were rescued from the office.

They included a lovable, just-retired captain named Jack Punches, 51, of Clifton, who had flown anti-submarine planes during the Cold War and was the master of the daily crossword puzzle; and a veteran Navy captain, Lawrence Daniel Getzfred, 57, who lived in Fairfax County and was one of five Nebraska brothers to serve in the Navy.

There were Naval Academy graduates, and sons of sailors, and people who flew the flag on their front lawns.

In many ways, it could have been any office anywhere -- a place where people gossiped, snagged candy off one another's desks and showed off pictures of their kids. But this was the Pentagon, and these people had intelligence jobs they didn't talk about and titles such as "watchstander."

They worked in the Navy Command Center, the sophisticated, round-the-clock hub that monitors Navy activities, plots movements for 317 ships and keeps an eye on political events around the world.

At 0700 every day, Vice Adm. Timothy Keating, a square-jawed, strike fighter pilot, would stride to the center for his daily briefing that the staff liked to call "Around the World in 15 Pages." This being the Navy, the weather was critical, and four or five officers would forecast the day worldwide -- rain in the Pacific, clouds over the Atlantic, temperature in the Southern Command. "The Navy Today" brief told the brass how many of the Navy's ships and sailors were at sea.

For most, the Pentagon billet was a good one -- a time when, for once, they could be near their families instead of on six-month deployments at sea. It was also an important ticket to be punched, a sign that you were on your way up.

Although the hours were long, there was time to play golf, be with the kids or go to school. Lt. Michael "Scott" Lamana, 31, of Alexandria, was taking night classes toward an MBA.

"A lot of smart young kids," Rear Adm. James M. Zortman, who runs the center, said yesterday, "lieutenants, petty officers who are real sharp. There are some older . . . faces, but the real energy comes from the younger people."

Here first flashed news of last year's terrorist attack on the USS Cole in Yemen, the downing of a Navy spy plane by the Chinese in April and the accidental sinking of a Japanese training vessel boat by a Navy submarine in February.

"When the phone rings," Zortman said, "it might be the wife or mother of a sailor, it might be the secretary of the Navy, or it might be anybody in between. But they have to be ready for any one of them."

It could be tense and tiring, but there was an esprit in the room that made it feel more like a ship than an office.

"It's a nerve center," Keating, deputy chief of naval operations, said yesterday. "It all stops right there. It was invigorating for an old geezer to come in and to be with these young Hall of Fame utility infielders who were doing such important work, and who were excited about it. It was exhilarating to go there. Every morning."

The entire room, including a section for the small Navy counter-drug task force, had just been renovated, as part of ongoing, long-term Pentagon renovations, officials said, and the moving began Aug. 15.

Many of the workers had come to the sparkling new quarters from the old command center and its adjacent offices on the fourth floor in another part of the building.

It was "like stepping from an old VW Bug to a big Cadillac," said Lt. William Wertz, 27, one of the center's watchstanders.

"Everything was new," said Sandelli, of Alexandria, who worked with the counter-drug group. "The furniture, floors, lighting, electrical. It had plenty of amenities that the old [offices] didn't have. It was very nicely done."

"We were still trying to get our telephones straightened out," Sandelli said, "that's how new it was. My phone rang at the next desk over."

But everyone seemed to click. "It was always just a good feeling," he said.

There were cubicles and private offices, and people had their spaces decorated with family photos -- Sandelli had pictures of him and his wife on their black Harley-Davidson -- wiseacre political slogans and "Beat Army" stickers.

Cmdr. Patrick Dunn, 39, who kept the office happy with jokes and talk of knocking off early, kept a big jar of candy on his desk. First Class Petty Officer Joseph Pycior, 39, was the command center's "Mr. Fixit." Both are officially missing.

On Tuesday morning, there were suit coats slung over chairs, briefcases on the floors and papers piled on desks. Most people had been at work since 0700 or 0730. They'd come by bus, Metro and carpool. The first pot of coffee had been made, and some meetings had already been held.

The first inkling of trouble came when Petty Officer Michael Allen Noeth, 30, who painted Navy posters and would shortly vanish in the inferno, jumped up at his desk and shouted: "My God! What's happened?"

He pointed to the World Trade Center calamity that was unfolding on the TV sets bolted to the wall. People quickly gathered around. A few old hands muttered to themselves that the Pentagon was probably next.

But work had to continue.

The phone rang on the orderly desk of Petty Officer Charles Lewis, 30, of the District. It was Jarrell "Jerry" Henson, 64, of Burke, a retired officer who had flown reconnaissance missions in Vietnam and who now headed the anti-drug group. Henson's travel arrangements to a conference were messed up.

Lewis stood up and grabbed another petty officer and the two headed down to the walled-off office that Henson shared with Punches. They waited patiently for both men to finish phone calls.

Paul S. Brady, 66, another retired officer who had served on a cruiser during the 1962 U.S. blockade of Cuba and was now a program analyst with the anti-drug group, was at his desk toward the back of the room, trying to concentrate on his work. A self-described "crusty old sea dog," he had pictures of his 10 grandchildren tacked to his wall.

And Rick Sandelli was headed for the stopped clock that hung above Brady's desk. "It was stuck at about 20 minutes to 10," Sandelli said, "it was probably more like 10 of 10." He walked up, stopped. "What a stupid clock," he thought. But before he could reach out, disaster struck.

What followed was a deep, thunderous roar as the hijacked airliner slammed into the outer, or E Ring, of the 59-year-old concrete hulk of the Pentagon at full throttle.

It sounded, said one former turret officer, "like a five-inch shell going off."

In Room 1D457, there was a rush of air, blackness and, for a few seconds, utter silence. When people came to their senses, the ceiling had collapsed, the fire sprinklers had come on and the room was quickly filling with smoke.

Petty Officer Lewis had been blown 15 feet across the room: "It sounded like a big gust of wind -- a big whooshing sound," he said. "You could feel it coming -- things were shaking and it was coming closer and closer."

Henson, who had been on the phone, suddenly found himself pinned in his chair by the choking debris. A few feet away, Sandelli was knocked to his knees. Brady immediately thought, "My God, they hit us."

Henson and Lewis wound up in the hospital. Sandelli, tattered and sooty and a little dazed, walked miles to a Metro stop and then more miles home. Brady found his car and drove home.

There were many in Room 1D457, though, who didn't make it out. Smart young kids, and crusty veterans.

It seemed bad for the older guys, like Jack Punches.

He was a guy, his friend Brady said, who had survived anti-submarine patrols in bad weather and touchy situations all over the world.

"Got through 20 years of that, with all the hazards," Brady said, "then gets killed in this mess."

It was bad for the devoted younger sailors, too.

"Every minute of every day, these young men and women were standing the watch," Adm. Keating said.

"That's what they were doing when they were attacked."

The Pentagon, where 124 are believed to have to been killed, has been considered a good assignment because it kept service people close to home.Navy employee Rick Sandelli, 48, had gone over to knock a clock into submission when Flight 77 struck. He was knocked to his knees by the blast. Some others in the same room were not as fortunate.Petty Officer Charles Lewis, 30, was injured when he was blown 15 feet across the room.