Its design team, including Arthur Dunnam, who is now the design director, remains largely intact. Though the firm has worked in a variety of styles, including Arts and Crafts, for which it was best known, it has recently added more contemporary and colorful interiors to its résumé. And if it lost clients when it lost Jed Johnson, it has gained clients who came to it for its 30 years of experience, not the presence of celebrity. Paul Goldberger, writing in The New York Times in 1996, shortly after the plane crash, said Jed Johnson had "one of the best eyes that has existed in our time."

Alan Wanzenberg, an architect, was Jed Johnson's personal partner and professional collaborator and was considered by many to be the heir apparent as the surviving half of a well-known team. They were also business partners in Jed Johnson, Alan Wanzenberg & Associates until 1986, when Mr. Wanzenberg established his own company, Alan Wanzenberg Architect, which continued to work with Mr. Johnson. He now has his own interior design business and does not work with Jed Johnson Associates, the successor to their earlier partnership.

Nancy Blank, who commissioned Mr. Wanzenberg and Jed Johnson to design a house in Pennsylvania before Mr. Johnson died, has since designed an apartment in New York with Mr. Dunnam and the firm.

"I'm sure Jed had an incredible eye, but so do other people there," Ms. Blank said. She added that she had met people who changed design firms when Mr. Johnson was killed, but explained that "a lot of times I've found, in that industry, so many of the 'wow' names are not professional."

"And bragging rights don't do it for me," she added, "as long as I have a great finished product."

Born in Alexandria, a small town in Minnesota, in 1948 -- Fargo was the nearest big place -- Jed and Jay were two of six children of an alcoholic father who brokered milk, eggs and pelts for local farmers, and a homemaker who divorced him when the twins were 18. The two boys could have been characters in a novel by Theodore Dreiser, or a story by Truman Capote.

Raised in Arizona, then California, where the family moved in search of employment, Jed and Jay arrived in New York, making the last leg by Greyhound bus. They took the subway to the East Village, found an apartment through a heroin addict, got mugged and lost their last $200, and took jobs delivering telegrams for Western Union. On his third day at work, Jed Johnson delivered a telegram to Andy Warhol's Factory on Union Square. And yes, the rest is history.

"It became very exciting, almost instantly," Mr. Johnson said of their careers as celebrities within Warhol's circle, traveling between New York, Paris, London and exotic points farther afield. "He worked much harder than I did," he said of Jed and his ambition. "I played much harder."

Jay Johnson drank heavily, favored cocaine, wore makeup, modeled and helped paint Warhol's pictures for the Factory. "Eric Boman also wore makeup," Mr. Johnson said of the fashion photographer, who is one of his oldest acquaintances. Another fashion acquaintance, Marina Schiano, called them "the two lesbians."

"We thought we were fabulously beautiful, and so masculine," Mr. Johnson said.

He also became friendly with some of the most dissolute citizens of the century, including Marianne Faithfull, the singer, and Henrietta Moraes, a British beauty and bohemian who was portrayed by the painter Francis Bacon naked with a needle in her arm (which was artistic license, as she was investigating LSD at the time), went to prison for burglary after her marriage to an Indian poet ended, and spent her last days in a single room in Chelsea with her dachshund, Max.