Soon after the World Trade Centers collapsed, the streets of downtown Manhattan were plastered with signs seeking missing people—pictures, names and descriptions of those not yet accounted for, posted by family and friends. But another group was absent even from the ranks of the missing: the undocumented immigrants working in the towers. Some of these workers have since been identified as missing; others remain nameless.

The families of illegal workers faced incredible complications in addition to the grief with which they were already coping. For those in the United States, coming forward to report their relatives missing meant attracting the attention of legal authorities and risking deportation. For the families of those working off the books, it was even more difficult to confirm their relative’s death. If a family could confirm a relatives death, compensation and relief were still sometimes denied if the family members were not citizens. Many of those outside the U.S. were in poor communication with their relatives in New York because of the conditions of illegal immigration, making it harder to recognize when someone was truly gone. Rosario Arrazola explained to The New York Times that she only surmised her husband’s death when their son’s birthday came and he didn’t call. He was in the United States illegally; to avoid being traced he did not communicate about where he was living or working.

Run up against an incredible loss, the families of victims were then once again run up against a hostile American immigration service and the realities of immigrant life in the American economy. Those conditions continue to keep invisible the stories of some of those killed in the towers.

While the repression of their stories is a tragic element of the American system, the tragedy of their deaths is not an American tragedy. Those who died a year ago were from both sides of America’s borders. The collapse of the towers was first and foremost a human tragedy, felt more acutely by families like the Arrazolas in Mexico than by most families in the United States who were not directly affected.

Yet America has laid claim to the tragedy of Sept. 11, breaking out the flags and revving up the war machine. The immigration system has become more strict—as though foreigners are more akin to terrorists than to normal people. The division between terrorist and victim, of course, has nothing to do with nationality. Those killed in the towers were people going about their work; those who killed them were engaged in unfathomable violence and destruction.

For our country to honor those Americans and foreigners killed in the towers requires more than waving a flag. We can and should unite, but not as Americans—indeed, some of those killed leave behind families unable to unite with and embrace America—but as people opposed to the sort of violence inflicted last Sept. 11.