FORT HOOD, Texas — Pfc. Marquest Smith, on his way to Afghanistan in January, was completing routine paperwork about a bee-sting allergy when the sounds erupted.

A loud, popping noise. Moans. The sudden, urgent shout of “Gun!”

Smith poked his head over the cubicle’s partition and saw an extraordinary sight: An Army officer with two guns, firing into the crowded room.

The 21-year-old Fort Worth native quickly grabbed the civilian worker who’d been helping with his paperwork and forced her under the desk. He lay low for several minutes, waiting for the shooter to run out of ammunition and wishing he, too, had a gun.

After the shooter stopped to reload, Smith made a run for it. Pushing two other soldiers in front of him, he made it out of the Soldier Readiness Processing center — only to plunge into the building twice more to help the wounded.

Smith had survived the worst mass shooting on an American military base, a rampage that left 13 dead and 30 wounded, including the alleged shooter, Army psychiatrist Maj. Nidal Malik Hasan.

It could have been much worse, but for the heroics of Smith and others — like the 19-year-old private who ignored her own wounds, and the diminutive civilian police officer who single-handedly took down Hasan.

“Unfortunately over the past eight years, our Army has been no stranger to tragedy,” said a somber Gen. George Casey, Army chief of staff. “But we are an Army that draws strength from adversity. And hearing the stories of courage and heroism that I heard today makes me proud to be the leader of this great Army.”

Home of the 1st Cavalry and 1st Army Division West, Fort Hood has seen more than its share of deployments and casualties in the past eight years.

As a psychiatrist, Hasan, 39, had listened to soldiers’ tales of horror. Now, the American-born Muslim was facing imminent deployment to Afghanistan. In recent days, Hasan had been saying goodbye to friends. He had given away many of his possessions, including copies of the Holy Quran.

At 2:37 a.m. Thursday and again around 5, Hasan called neighbor Willie Bell. Bell could normally hear Hasan’s morning prayers through the thin apartment walls, but Hasan skipped the ritual Thursday.

Bell didn’t pick up either time, but Hasan left a message.

“Nice knowing you, old friend,” Hasan said. “I’m going to miss you.”

At the processing center on the southern edge of the 100,000-acre base, soldiers returning from overseas mingled with colleagues filling out forms and undergoing medical tests in preparation for deployment.

Around 1:30 p.m., witnesses say a man later identified as Hasan jumped up on a desk and shouted the words “Allahu Akbar!” — Arabic for “God is great!” He was armed with two pistols, one a semiautomatic capable of firing up to 20 rounds without reloading.

Packed into cubicles with 5-foot-high dividers, the 300 unarmed soldiers were sitting ducks.

When he decided that Hasan wasn’t close to being out of ammo, Smith made a dash for the door. He’d made it outside when he heard cries from within.

“I don’t want to die.”

“Help me get out of here.”

Smith rushed back inside and found two wounded. He grabbed them by their collars and dragged them outside.

Around this time, Fort Hood Police Sgt. Kimberly Munley got the call of “shots fired.”

Munley, 34, was on the scene within three minutes.

Just over 5 feet tall, Munley is an advanced firearms instructor and civilian member of Fort Hood’s special reaction team. She had trained on “active shooter” scenarios after the April 2007 mass shooting at Virginia Tech. She didn’t wait for backup.

As she approached the squat, rectangular building, a soldier emerged from a door with a gunman in pursuit. The officer fired, and the uniformed shooter wheeled and charged.

Munley was hit at least three times in the exchange — twice through the left leg and once in her right wrist. Hasan was hit four times.

From the first shots to the last, authorities say the whole incident lasted less than 10 minutes.

Next door, at the Howze Theater, Spc. Elliot Valdez was filming a graduation ceremony for soldiers who’d completed correspondence courses. Several proud scholars were posing for a group shot when Valdez heard a pounding at the side door.

The door burst open and the theater filled with shouts of “Medic!” and “Stay in the building!” A combat videographer who returned from a 15-month Iraq tour in January, most of it in the notorious Sadr City slums, Valdez ran out into the sunlight.

Crouching as he continued to roll tape, Valdez could see windows broken by fleeing victims. A soldier in his Class A dress uniform lay on the grass, a gunshot wound in his back. Soldiers in flowing black graduation robes and purple sashes rushed to help.

Pfc. Amber Bahr, 19, of Random Lake, Wis., tore up her blouse and used it as a tourniquet on a wounded comrade. It was only later that she realized she’d been shot in the back, the bullet exiting her abdomen.

Sgt. Andrew Hagerman, a military police officer, was patrolling a housing area when word of shootings crackled over his radio.

As he arrived at the processing center, bloodied soldiers, some shirtless, were already treating each other on the grass outside, ripping pant legs off and tying off wounds. Munley — with whom Hagerman had exchanged small talk on patrols — was being loaded into an ambulance.

Hasan lay on the ground, his two handguns beside him, as medical personnel struggled to remove his handcuffs to treat his wounds.

Hasan, hooked up to a ventilator, was moved Friday to a military hospital in San Antonio. The woman who stopped him, Munley, awaited surgery Friday to remove the bullets from her leg. Her husband was flying in from Fort Bragg, N.C.

Marquest Smith says some of the people he helped made it. But he knows others did not.

Afterward, Smith noticed a hole in the heel of his right combat boot. A bullet had entered the boot, but he had somehow escaped injury — at least the physical kind.

After the adrenaline wore off, Smith was overwhelmed by a sense of betrayal, because this assailant who spilled so much blood was a soldier.

“We’re supposed to be a family,” he said.