The number of U.S. troops who have died in the Iraq war hit 2,000 yesterday, a toll felt deeply at big military bases across America that active-duty soldiers and families call home, as well as in hundreds of communities where the National Guard and reservists work, live and train.

The threshold was crossed with the Pentagon's announcement that Staff Sgt. George Alexander Jr., 34, of Killeen, Tex., had died at Brooke Army Medical Center in Texas on Saturday of injuries suffered in Iraq earlier this month, when a bomb planted by insurgents exploded near his Bradley Fighting Vehicle.

Since the March 2003 invasion and quick march to take Baghdad, U.S. troops have been dying at about 800 a year, with most killed in action by crude but powerful roadside bombs and in firefights against an unrelenting insurgency. More than 90 percent of the deaths have come after President Bush declared an end to "major combat operations" on May 1, 2003.

The deaths in Iraq are relatively few compared with other wars in U.S. history, and they pale dramatically in comparison with the losses in the two world wars, when the United States saw a combined total of more than half a million fall. The Iraq death total also falls far short of the worst nine years of the Vietnam War, from 1964 to 1973, when more than 58,000 U.S. troops did not return, an average of more than 6,400 deaths a year.

Unique to the war in Iraq, however, is the way in which the combat deaths are hitting home, with the Guard and reserves paying a high price because of their unprecedented involvement overseas. While accounting for about a quarter of those killed, such citizen-soldier units in recent months took especially heavy losses, sending the shock of death throughout cities and towns in most every state, sometimes in devastating clusters.

"This is exponentially beyond anything we've seen since World War II," Lt. Gen. H Steven Blum, chief of the National Guard Bureau, said in an interview. "The casualties are felt not only in the immediate family but in the community . . . so the loss is shared and felt even beyond the lives of the normal tragedy. When you call up the Guard, you call up America. It's significantly why the American people continue to support the soldiers even though they may not support the way the war is executed or even [that] we went to war."

The daily casualty tolls are not usually big enough to jar the American public as a whole, apart from events such as helicopter crashes, a suicide bombing at a chow hall or rare heavy losses in battle. Yet flag-draped coffins arriving from Iraq at the rate of two or three each day visit grief upon one town after another -- posing in intimate terms stark questions about the war.

The past two months have been particularly cruel to Pennsylvania, which has lost 15 National Guard soldiers in a series of catastrophic incidents. In one 60-mile stretch of rural northeastern Pennsylvania, tiny towns dotting the Blue Ridge mountains lost several men from one platoon of the local Guard unit -- Charlie Company of the 1st Battalion, 109th Infantry Regiment -- in 10 days of fighting last month in Ramadi.

The death of Spec. William "Bil" Evans, 22, on Sept. 19 in a Bradley Fighting Vehicle, ripped through Hallstead, Pa., early the next morning. Immediately, the town of about 2,000 rallied behind his parents, Judy and Bill, as everyone struggled to comprehend it.

Evans joined the National Guard as a way to pay for college. An aspiring photographer, he had his eye on a school in Ohio and strove for a job at National Geographic, his parents said. Evans never figured he would get sent off to combat because the unit had recently served a tour in Bosnia, and he found great camaraderie in the Guard.

"None of them ever thought that they would actually go to war," said Bill Evans, an Air Force veteran, glancing at his son's array of posthumous medals and the flag that draped his casket. "None of them ever dreamed that some of them wouldn't come home."

As the Evans family prepared to put on a viewing for their oldest son on Sept. 29, tragedy hit the region again, the news spreading from house to house in towns such as Carbondale to the south, Athens and Montrose to the west, and in tiny Great Bend, which neighbors Hallstead across the north-flowing waters of the Susquehanna River.

Five more soldiers from Charlie Company had died the day before.

Jessica Wiegand, 21, of Great Bend was about to leave her home for the Evans viewing when a car pulled up and a uniformed officer got out. She knew immediately that her husband, Spec. Lee A. Wiegand, 20, wasn't coming home.

In the days after Evans's death, Jessica Wiegand had noticed a change in the tone of her husband's Internet messages; he had gone from excited about what he was doing to increasingly scared about what might happen.

"He just kept telling me that he loved me and that he would be coming home," Wiegand said, her 5-month-old daughter, Jordan, cooing in the next room. Lee Wiegand saw his daughter only briefly after he was mobilized to deploy. "No one expected anything like this to happen, even with what happened to Bil. It wasn't going to happen to this town again."

The news that five more soldiers had died spread through the viewing line at Evans's church, and more than 2,000 people streamed in over more than eight hours. Those who attended said they were stunned. Many people say, even a month later, that they are still numb.

Donald Littleton, pastor of the United Community Methodist Church in Great Bend, said people have been grappling to describe how the town has changed. He said he believes people have been deeply emotionally affected by the deaths, in part because the war is no longer an abstract concept in the news, but "it's now on our doorstep, it's here, and we have to realize that the war is real."

Sgt. 1st Class James B. Ditchey has felt the losses intensely because he recruited into the Guard all but one of the six soldiers, and he considered all of them family. He said the community has in some ways lost its naivete.

"I never ever thought that I'd have to bury any of my privates. Never," Ditchey said. "My biggest fear was having to face a family like this because I know all the families. I've now had to face it six times."

News has been similarly grim in Maryland, which in the past two weeks lost five service members: three National Guardsmen, a Marine and an active-duty soldier. Since the war started, 84 troops from Maryland, Virginia and the District have died, including six in the National Guard and four reservists, according to records compiled by The Washington Post. Virginia has lost 53 troops, Maryland 28. Three from D.C. have died.

The 2,000 mark was recorded yesterday in counts kept by The Post and other news organizations based on information released by the military. The Defense Department's official casualty number, however, generally lags -- it stood yesterday at 1,993 -- because it includes only troops who have been officially identified and whose families have been notified. Pentagon figures show that more than 15,000 have been wounded.

The U.S. military has provided no comprehensive estimate of deaths among Iraqis -- either insurgents or non-combatants. Based on fragmented reports, the number of enemy Iraqi fighters killed appears to be several times greater than the U.S. fatalities, while independent estimates of the number of dead Iraqi civilians range from 20,000 to 30,000.

As in any war, the worst toll in Iraq has been borne by young, male ground troops: Three-quarters of the dead are active-duty soldiers and Marines, the bulk of them in their twenties.

Yet the large presence of National Guard and reserve troops in Iraq -- which peaked at nearly half the total earlier this year -- means those dying are more likely to be older (a quarter are over 30), married (40 percent) and parents (30 percent).

In Vietnam, 10,000 National Guardsmen served, accounting for about 100 deaths, according to official figures. In the Gulf War, no Guard troops died in combat, and only a handful succumbed to accidents and illness. In contrast, since Sept. 11, 2001, more than 250,000 Guard troops have been mobilized to fight terrorism -- including tens of thousands sent to Iraq.

Historians question how much the war's resulting spread of suffering into the far reaches of America will affect political support for the Iraq conflict -- a worry that caused President Lyndon Johnson to keep the Guard home during Vietnam, experts say.

"They were afraid the American public would turn against them because they took all these casualties in one small town," said Maj. Les A. Melnyk, a National Guard Bureau historian. "The fear is the Guard is more vulnerable to public backlash over casualties."

In a scene playing out in different ways in small towns across America, the war deaths swirled in discussion at the local cafe and farmer's market last Friday in Montrose, the seat of Susquehanna County. People said they now see the war in a harsh new light, realizing that the soldiers who are giving their lives aren't from someplace else, they're like Staff Sgt. Daniel L. Arnold, 27 -- from their borough.

"It just drove the horror of war closer to home," said Tom Pascoe, 60, a Montrose dentist. "The stakes of the game are far more vivid."

At Susquehanna Community High School on Friday, the student body honored Evans and celebrated his parents with an emotional ceremony. Evans attended elementary school in the district, and school officials wanted to show their support. Students lined the halls and applauded as the Evanses embraced and slowly walked through the din, tears streaming down their faces.

Blue Ridge High School, from which Evans and Wiegand graduated, is reviewing plans for a memorial, hoping to use bluestone from nearby quarries. Still, many wonder if they could handle more bad news.

"The military is a good option for some of the kids around here," said John Manchester, the high school's principal. "I'm sure there are a lot of mothers and fathers out there who don't want their children signing up right now. . . . I'm not sure I can take another hit. After a while you wonder when it's going to end. This is a small area, and there are just so many ties here."

Maj. Gen. Jessica L. Wright, Pennsylvania's National Guard adjutant general, said she has been meeting with the families who have sacrificed their children, husbands, siblings and parents for the war, and she described it as "devastating."

In a telephone interview, Wright nearly broke down when talking about meeting with the family of Spec. Eric W. Slebodnik, 21, of Carbondale, who was one of the five killed on Sept. 28. Slebodnik's remains have not yet been returned to his family, and his funeral will be the last of the six who were from northeastern Pennsylvania.

In addition to Evans, Wiegand, Slebodnik and Arnold, two other soldiers died in the two incidents involving Charlie Company's attacks: Spec. Oliver J. Brown, 19, of Athens, and Staff Sgt. George A. Pugliese, 39, of Carbondale.

"Pennsylvania has been hit really hard in the past two months, and words just don't describe the hurt you feel when that happens," Wright said. "The Guard is a community-based organization. When we send a soldier to war, we send their town to war."

The daughters of Lt. Col. Leon James II -- from left, Kathryn, Maria and Rachel -- attend his funeral at Arlington National Cemetery. The officer died at Walter Reed hospital on Oct. 10 after suffering injuries in Baghdad on Sept. 26. Two fellow soldiers died the day of the attack on their Humvee. Story, B2.