Year of Struggle and Change:

When the World Trade Center towers fell, they took more with them than human lives. A huge segment of the downtown economy collapsed with the falling steel and concrete, and the disaster encompassed far more than the large financial firms that are most often identified with the Sept. 11 attacks.

The trade center was home to hundreds of diverse companies, a polyglot village spanning everything from Asian food importers to graphic designers to dentists. Many had inhabited the towers for decades.

Those companies, more than half of which had fewer than 20 employees, became refugees on Sept. 11. Some have folded, overwhelmed by the deaths of owners or employees or undone by a lack of cash. Others have eked out a living in kitchens and basements. Some have relocated to Florida or Texas, while others have insisted on staying within a few blocks of ground zero. Some, miraculously, have flourished, growing even as the local economy foundered.

The New York Times set out to chronicle the fate of the complex’s tenants as they struggled to re-establish themselves over the past year. After compiling lists of tenants from several sources, The Times estimates that about 700 companies and organizations occupied the trade center buildings. Defining a more precise number, however, is difficult because so many of the companies were subtenants whose occupancy did not appear on official lists.