Every year, it seems, there are one or two items that are so popular as holiday gifts, stores have trouble keeping them in stock. This year, it is anything to do with New York City's firefighters, who have become national heroes in the aftermath of the terrorist attacks on the World Trade Center.

Miniature fire trucks, fire-fighter action figures, T-shirts, jackets and baseball hats - all emblazoned with FDNY, the mark of the New York City Fire Department - that's what's flying off the shelves this holiday shopping season.

Mary Weitzman, executive director of the FDNY Fire Safety Education Fund, which is the chief beneficiary of official FDNY merchandise sales, is amazed at the demand. "Our business is up 1,000 percent. ? On the Web site alone, we've gone from taking 30 orders a day to 300," she said.

Sally Reynolds was shopping at the Fire Zone, one of three places in New York selling official FDNY merchandise, that is, merchandise benefiting the FDNY. She, like others shopping there, expressed her deep admiration for New York's firefighters. "He's the hero of the year. He's New York's hero. He's everybody's hero," she said.

For New York firemen like Kevin Hannafin, a 19-year-veteran who lost his brother in the September 11 attack on New York's World Trade Center, the frenzy over everything with the FDNY mark is simply another component in a welcome show of appreciation for what he does. "We as firefighters know that we have been the first line of defense in this country, and firefighters worldwide - this is that brotherhood," he said. "We know we've been there, and now the whole world knows that we've been there all along. And we will continue to be."

Items honoring New York City's firefighters are for sale all over the city, but official merchandise is only available at The Fire Zone in Rockefeller Plaza, the Fire Zone boutique at the Bloomingdale's department store, and the Fire Museum on Spring Street.