The most excruciating loss suffered in the terrorist attack on the World Trade Center can be measured only in human lives. But the loss of the twin towers themselves has left a hole in New York's skyline that, like an amputated limb, will continue to cause residents and visitors to feel a visual version of "phantom pain" as they seek an architectural point of orientation that is no longer there.

Already, there have been calls for the reconstruction of the towers as a sign of American resolve, and that wish to begin the physical recovery is perfectly understandable. But we also have a civic and moral obligation to commemorate the destruction. We tend to memorialize with art, as in Oklahoma City, but in this case, the rubble itself needs to be the memorial. The most effective way to do that is to preserve a large section of the ruin as a visual expression of loss.

As the World Trade Center's rubble is slowly ferried to Fresh Kills landfill on New York's Staten Island, I am reminded of the creation of "rubble mountains" in German cities after World War II. In Munich, for example, some 5 million cubic meters of rubble were piled in soaring heaps, covered with earth, and gradually reclaimed by nature. These sites evolved into hilly public parks that were often graced with memorials commemorating the civilian victims of the war as well as the city's physical remnants, which lie beneath.

New York will not see the creation of rubble mountains, but it will face the same challenge of preserving the memory of atrocity once the rubble has been removed. I use the term "challenge" deliberately, for the natural human response to destruction is immediate reconstruction. Americans pride themselves on their capacity to bounce back from tragedy. But we should resist the temptation to sweep aside all the signs of destruction from the site in racing to redevelop it.

For while it is understandable, the rush to reconstruction complicates the process of mourning. Human beings invariably gravitate to the sites of tragedy -- especially ruins -- as part of the larger process of grieving. Ruins have played an important role in the cultural geography of Western society. As symbols of transience, decay and death, they have long served as evocative sites for people to attempt to come to terms with loss. The French preserved the entire ruined village of Oradour-sur-Glane after it was destroyed and most of its residents massacred by the Nazis in 1944, as a symbol of French martyrdom. The British maintained the burned-out shell of the 12th-century Coventry Cathedral and other heavily damaged churches for similar reasons. Such resonant sites do not lose their evocative power over time. Jews have prayed and wept at the ruin of the Western Wall of the Second Temple ever since its destruction by the Romans in the year 70 C.E.

By contrast, the disappearance of authentic sites of tragedy makes coping with the past more difficult. Immediately after the Berlin Wall began coming down in 1989, for example, nearly all remnants of the concrete monolith were destroyed as unpleasant reminders of an authoritarian past. A decade later, however, many Berliners regret the near wholesale eradication of the wall, for they now largely lack authentic sites at which to reflect upon their recent history of division.

Unlike Europe, ruins have seldom been a part of the American urban landscape. Nor have the scars of foreign attack. The Revolutionary War and the War of 1812 did not leave significant marks on the landscape. And our own self-imposed destruction during the Civil War has long been more visible at memorial sites such as Gettysburg, where more than 1,400 monuments were erected decades after the war, rather than at the scattered pockmarked buildings in the South, such as the state house in Columbia, S.C., which displays the war's destructive effects more directly. Finally, the only visible signs of World War II's impact within America's borders lie far from the U.S. mainland, half-hidden underwater at Pearl Harbor.

Without having suffered large-scale urban destruction, America has generally left the task of commemorating its tragedies to monuments and memorials, as was shown yet again by the recent opening of the National Memorial to the victims of the 1995 blast at the Alfred P. Murrah Federal Building in Oklahoma City. This memorial, composed of a field of 168 empty chairs symbolizing the blast's victims, is an extremely moving work of art. Yet, like most memorials it conveys a sense of the destruction through the distancing means of aesthetic mediation rather than through the more direct preservation of the ruin itself.

Now, however, America has experienced the pain of urban destruction that Europeans know all too well. Like them, we should learn to live with ruins. In the coming months, architects will be submitting plans to guide what will be a reconstruction project unlike any other in American history. The economic reasons for rebuilding such a valuable piece of Manhattan real estate are clear. But it will not be enough to install a token piece of sculpture or other public art to mark the horrible events of Sept. 11.

Some may find it premature, distasteful, perhaps even impious, to contemplate so early in our grieving preserving portions of the ruins. But we must. For many years to come, Americans will have a psychological need to visit the site of the worst enemy attack in American history to reflect, remember and mourn.

Since the attack, what remains of the World Trade Center's sheared-off facade, sprouting up from the ground at bizarre angles like metallic weeds, has acquired iconic status as the symbol of the catastrophe. Before long, however, these remnants will likely be demolished and carted away from the site along with the hundreds of thousands of tons of rubble still waiting to be cleared.

For now, they stand. And as long as they stand, these haunting vestiges of the vanished towers will be able to evoke the recent past better than any commissioned monument will ever be able to do. I think if the European experience of reconstruction after the Second World War teaches us anything, it is that there is room for preserving the memory of tragedy alongside the pursuit of recovery. It is important that the lessons of this painful moment in history -- unclear as they may yet be -- not be entirely overshadowed by the new works of architecture destined to be built on the site of tragedy.

Gavriel Rosenfeld is assistant professor of history at Fairfield University in Connecticut, and author of "Munich and Memory: Architecture, Monuments, and the Legacy of the Third Reich" (University of California Press).The remains of the World Trade Center, as seen through the haze last week.Above: Coventry Cathedral in England, as it was left in 1946. Below, the Western Wall in Jerusalem, as it was felt by an Orthodox Jew during the high holidays.