September 11, 8:50 a.m. Sgt. Charlie Wilson was in a police van, racing south toward the World Trade Center. He had gone on call six hours before, having been posted at Times Square in preparation for Election Day.

Five minutes earlier, his radio had screamed to life when American Airlines Flight 11 slammed into the north tower of the World Trade Center. When Wilson looked up and saw the burning tower spitting fire on the huge television screen above Times Square, he jumped in his van and headed to his precinct, Midtown South, picking up eight policemen for the drive downtown.

The van wouldn't make it all the way to the towers.

"A bunch of pedestrians jumped in front of the van," says Wilson, 43, a man of average height with glasses and a mustache. "A woman was hurt -- half her foot was blown off."

Wilson and seven of his men left the van, putting the injured woman inside. The driver turned for the hospital while the eight cops ran toward the Twin Towers. They were five blocks away when the second plane -- United 175 -- hit the south tower. It was 9:03, and for Wilson the day wouldn't end until 2:30 the next morning. The nightmare will stay with him forever.

Before September 11, New Yorkers had reason to view their police with a wary eye. The 1999 killing of Amadou Diallo, slain in a hail of police gunfire, and the brutal 1997 torture of Abner Louima in a police department bathroom had stained the department's image. "We were in the dumps," says Patrolman Tim Burke, 41, a 20-year veteran of the NYPD stationed in the South Bronx. "We had some very bad publicity."

The department traces itself to very humble beginnings. New York's earliest policemen were the Burgher Guard, a group of eight night patrolmen created in 1658 by Dutch settlers to watch for fires and raids. For almost 200 years, the city experimented with different forms of part-time law enforcement -- some paid constabularies, some volunteer patrols. All efforts were undermanned. None were very efficient, and the city crawled with crime. Eighteen-thirty-four became known as the year of the riots, and in the Five Points neighborhood in lower Manhattan, where Park, Worth and Baxter streets intersected, one murder a night was said to take place. After a visit in 1842 to Five Points, Charles Dickens described the streets as "reeking everywhere with dirt and filth."

With nearly 400,000 residents, New York clearly needed protection. In 1845, the city created America's first full-time professional police force, with 900 men. They wouldn't get uniforms until 1853, however.

New York remained tough. The West Side neighborhood of Hell's Kitchen was one of the city's most notoriously crime-ridden areas, home to several gangs. Police were said to walk those streets only in pairs.

Police corruption was frequently a problem, but heroes soon rose from within the department's ranks. In 1895, Theodore Roosevelt became police commissioner, three years before he would lead the Rough Riders into Cuba. One of Roosevelt's moves as New York chief was reining in Alexander "Clubber" Williams, a tough, corrupt cop who won his nickname by swinging his nightstick with particular ardor. "There is more law at the end of a policeman's nightstick than in all the decisions of the Supreme Court," Williams bragged. Roosevelt forced him into retirement.

Lt. Giuseppe Petrosino, the department's first Italian-American detective, founded the city's bomb squad to fight the Black Hand, an early version of the Mafia. He was murdered in 1909 in Palermo, Sicily, while gathering intelligence against the Black Hand. He remains the only NYPD officer killed in the line of duty outside of the United States.

Heroism like Petrosino's has a long tradition in the New York City police department, and the officers who responded to the September 11 disaster -- the department's bloodiest day -- carried it out valiantly. The police marched forward as civilians ran for safety. They dug for buried comrades in the wake of the collapse. And they listened in pain as their brothers died.

The horrid, unforgettable roar of a jet slamming into the steel and glass behemoth of Two World Trade Center shocked Sergeant Wilson as he and his men raced to the crime scene. A parade of injured streamed by. "What freaked us out was there were businesspeople running past us, burned on the face. They were completely fried, but they're not stopping." The team finally made it to the towers. Both were in flames.

It was only minutes after the second impact, but the ground already resembled a battlefield. Body parts and the mingled wreckage of airplanes and skyscrapers littered the street. A massive airplane tire sat in the middle of the block, being guarded by an FBI agent in shock. Above, people were jumping.

The jumpers will haunt Wilson for the rest of his years. Women with their purses. Men clutching their briefcases, papers streaming as they fell. One man desperately held a tablecloth, perhaps hoping to fashion a parachute; another fell gripping an office chair. The most haunting vision was the couple. "They stood out, held hands and jumped," says Wilson. "They held hands the whole way down."

With the world coming apart around him, Wilson tried to maintain order. One of his men tried to say a Hail Mary as each jumper leaped to escape the inferno. "He couldn't keep up. Finally I had to tell him, 'Enough,' " says Wilson.

A fellow officer directed rescuers at the base of the trade center, his eyes looking up, trying to keep the rescuers and those fleeing on the ground safe from the people above.

Wilson, like most observers, expected the towers to remain standing. "I never expected that thing to come down," he says.

Rescue workers -- police, firefighters, paramedics -- filled the staircases as the first building collapsed. The police had a chilling window on the death throes of their fellow officers, who called for help on their radios.

"I was on citywide radio listening to the screaming of our brothers and sisters," says Patrolman Burke. Officer Moira Smith was trapped inside the north tower as it collapsed. The injured Smith radioed for help, describing her position. "She was doing a great job," says Burke. "She was very calm," says Wilson. "She just faded away." Smith is believed to be the first female officer in the NYPD to die on duty, one of 60 NYPD and Port Authority police officers to perish in the World Trade Center.

To put that number in perspective, consider that the most NYPD officers killed on duty in an entire decade is the 57 police lost in the gangland violence of the "Roaring Twenties."

Burke, a union delegate for the department, lost one man, officer John Perry. Many of the victims -- police and firefighters alike -- weren't on duty that day, but Perry wasn't even supposed to be a police officer on September 11: that morning, he had gone to One Police Plaza to resign.

"He was putting in his paper to resign," says Burke, "but they were evacuating the building." Standing outside police headquarters, Perry met up with a captain and raced to the World Trade Center, thoughts of resigning gone. The captain and Perry were separated. The captain survived; Perry died.

When the towers collapsed, Wilson and his men were covered in soot and debris. "It was like a tornado," says Wilson. Above, the roar of American fighter jets sounded like a new attack. In the blackness, people cried for help.

In the ruin of the towers, a bucket brigade was assembled in a frantic search for survivors. Burke stood on the ruined mass of steel and dust that had been New York's tallest buildings. "We stood on top of the World Trade Center," says Burke, a thickly built man with a crew cut and heavy mustache. He had never been to the top of the building when it was intact.

Burke was at the front of the line, digging. "I lost a man," he says. "You want to get down there and get your fingers dirty, your knuckles scraped. I needed closure. I needed to do something. I got choked up. I cried my eyes out."

Crying has become a familiar ritual for these police. Detective Herb Fonseca, a 19-year veteran of the NYPD, is a quartermaster of sorts, providing the equipment and supplies required at Ground Zero and the Fresh Kills Landfill on Staten Island. Months after the attacks, grief is now an integral part of his days and nights. "If you cry once a day, you survive," he says with a small smile.

Officers struggle to find words for their families, steeling themselves in front of loved ones. "My daughter knew [what was going on]," says Sgt. Ricardo Estupinan, 38, who, with his partner John Albarano, evacuated the Empire State Building on September 11. "My son is three and a half, but he knew something is wrong. And I hated him knowing. I said, 'Bad guys did bad things.'"

Some good has come of September 11: the city of New York has learned to love its police. Where officers were sometimes met with glares and hatred, citizens now cheer. Burke, exhausted and riding home from a long day at Ground Zero, heard screams along the West Side Highway. He thought it was a riot, and lifted his weary head.

"All these people were screaming, 'Thank you! God bless you!' They were an inspiration. As tired as I was, it gave me a boost. I have to let people know how inspirational those people were." Burke pauses, the memory heavy on his face. "I love to joke, but there's something about this Trade Center," says Burke. "My whole life, nothing's affected me more than that day. That beautiful Tuesday morning." The pain bleeds through his words.

New York City rallied to the side of its police force. Ordinary Joes lugged water. Volunteers passed out sandwiches to grimy rescue workers. Hotels opened their doors for a clean bed and a fresh shower. Restaurateurs brought in steaming pots of soup.

"People came from all over this world to help," says Burke. "There were a lot of heroes that day."

Wilson welcomes the change, but worries if it will last. "I'm a staunch Republican, a flag waver," he says. "Now it took this for everyone to get their flags out. It's a shame that it came to this to bring the country together. I just hope people don't forget two years down the line when we're still fighting this thing."

Photo by A. Perry Heller