Lt. William Stout, head of the Pentagon police force protection branch, was at home in Arlington playing with his 6-month-old son when he heard that the Pentagon had been hit by a hijacked airplane.

He knew local roads would be jammed, so he grabbed his bike and pedaled to the site. He arrived to find people streaming from the building, many burned and injured.

"It was surreal," said Stout. "As police, you train for a lot of incidents and scenarios. But nobody ever expected a plane to drop out of the sky and purposefully crash into our building."

Six weeks after the Sept. 11 crash, memories of that day are particularly vivid for the first responders, the 250 members of the Defense Protective Service, known as the Pentagon police, whose officers are charged with protecting the 40,000 people, half of them Department of Defense employees, who visit the building each day.

They are the unsung heroes of the Sept. 11 attack, yet their efforts have gone largely unnoticed. There were very few mentions of their heroism in early news reports. Their most public accolade came during a memorial service Oct. 11 when Defense Secretary Donald H. Rumsfeld thanked the service for their work.

The Defense Protective Service was established in 1987 to provide police service for the Pentagon and 40 other buildings in the Washington area that house Department of Defense employees. The agency, which includes a branch of unarmed security guards, includes a personal security unit, an emergency response team, a bomb detection canine unit, critical incident negotiators, a patrol division, bike patrol and a remote delivery facility, where every piece of mail, flower or box of candy is thoroughly inspected before being taken into the Pentagon. The officers respond to about 15,000 calls a year and make arrests for everything from rape to narcotics to traffic offenses.

Since the terrorist attack, Pentagon police have stepped up security measures with employees, visitors and commercial vehicles. Pentagon police Chief John Jester said the agency was still operating at high alert when the United States began a bombing campaign in Afghanistan on Oct. 7, sending them into an even higher security status, which continues.

"The difference between other people who came to help that day and us is they got to go home, but we're still here," said Pentagon police Capt. Randall Harper. "We look at it every day."

Praying for His Fiancee

Sgt. William Lagasse was at a gas station near the Pentagon filling up his patrol car when he noticed a jet fly in low.

Initially, he thought the plane was about to drop on top of him -- it was that close. The son of an aviation instructor, he knew something was wrong. The 757's flaps were not deployed and the landing gear was retracted.

He watched as the plane plowed into the Pentagon. He grabbed the medical bag that all Pentagon police carry in their cars and dashed for the crash site.

Doors had blown off the building and windows had melted from the heat.

Then, there was a series of supplemental explosions as cylinders of compressed gas at a construction site near the entrance of "Wedge One," the point at the south side of the facility, detonated because of the intense heat.

"The fire was out of control," he said.

After helping to pull people out of the rubble, Lagasse, 30, of Fredericksburg, worked to gather evidence at the crime scene, which he later shared with FBI investigators, along with his recollections of the airplane's actions. Pieces of the airplane had blown hundreds of yards away. Victims, some with cuts and burns, were bringing him pieces of debris.

As he worked, he prayed for his fiancee, Pentagon police Sgt. Sarah Austin, and her mother, Ann Marie Khinoo, who works for the undersecretary of the Navy.

Earlier, Austin had briefed her patrol officers on the attack at the World Trade Center during roll at the start of the first shift Sept 11.

"Be aware out there," Austin told the officers gathered in Room 2E165 of the Pentagon. "Heighten your senses a little."

At one point as they worked, Lagasse saw Austin in her police car. They hugged.

"We were both teary-eyed," Austin said.

'Daddy's Not Dead' After he heard about his father's workplace being hit by a hijacked airplane Sept. 11, 4-year-old Arvel Bright had one question:

"Is my Daddy dead?"

Mark Bright, 32, of Clinton in Prince George's County, a traffic division master patrol officer, was standing at the security booth at the Mall entrance of the Pentagon when he heard a loud noise, like an airplane revving up for takeoff.

"The next thing, you could see the plane . . . bank over these trees and come right toward the Pentagon," he said. "When it hit, it just exploded."

Seconds later Bright was at the tower at the Pentagon's heliport, a few feet from where the plane had hit. Black smoke was billowing out of the huge hole in the center of the building. People were jumping out of windows. He ran inside and started dragging people out. He remembers a woman with burns with bright red hair. He remembers a man walk out with no injuries at all.

"He said he was in the restroom," Bright said. "He gave us details of what had happened inside."

As Bright pulled victims from the building, his brother Joseph, a D.C. firefighter, helped battle the blaze. When the brothers crossed paths, "we just hugged," Bright said.

Later, Bright called his wife, LaJuan, and children at home.

"Daddy's not dead," he told his son as he fought back tears.

Fears of a Second Plane

Officer Isaac Hoopii, of the Pentagon police bomb detection canine unit, was at the Fort Myer veterinarian's office with his dog Vito when a radio broadcast notified him the Pentagon had been attacked.

Hoopii, 38, of McLean, a burly Hawaiian who plays guitar and sings in a band called the Aloha Boys, thought he had heard wrong.

But when the dispatcher confirmed the attack, he dashed for his patrol car, blowing his transmission on the short ride to the Pentagon.

At the site, Hoopii joined other Pentagon police officers working to rescue people from the burning building. The scene was total chaos -- screaming and yelling and explosions and noise and fear of another attack. Hoopii ran inside and pulled several people to safety. Then, firefighters who had arrived barred officers from a hot spot on the first floor. The black smoke and heat made it impossible for anyone to survive inside without adequate gear. Instead, Hoopii guided several people out by telling them to follow his voice.

A half-hour after the original Pentagon attack, Pentagon police got a report that a second plane was headed for them. They prayed they would be safe and kept working.

The second plane never arrived; a second plane headed for Washington crashed in western Pennsylvania. The officers were relieved when the Federal Aviation Authority suspended flights and Reagan National Airport was temporarily closed.

Now, planes are flying over the Pentagon again.

And while they go about their daily tasks, the Pentagon police are still keeping a wary eye on the sky.

"You can't think about it, you just have to do the job," Hoopii said. "There are so many people depending on us to make sure things are safe."

Pentagon police Officer Isaac Hoopii, left, and his dog Vito inspect trucks for possible bombs. Above, police Lt. William Stout, center, has early morning duty as Pentagon employees line up for identification and baggage checks."We look at it every day," said Pentagon police Capt. Randall Harper, left, here patrolling with Lt. William Stout.