Washington ? In the nation’s capital, there’s a welcome sight.

Tourists are again crowding into Metrorail cars and spilling through museums — signs the city’s top private industry is recovering from the slide that followed the Sept. 11, 2001, terrorist attacks.

The attacks on the World Trade Center and the Pentagon have cost Washington millions of dollars in tourist revenue. Anthrax, sniper shootings, the Iraq war, an unusually snowy winter, color-coded terrorism alerts and a weak economy haven’t helped.

According to Washington’s Convention and Tourism Corp., the number of domestic visitors in 2002 dropped 3 percent to 17.6 million. Those who came spent more than $4 billion in the district and its suburbs.

“We’re hoping that this year we’ll get back to the pre-9-11 levels,” said WCTC president William A. Hanbury. “It has been challenging, not only for Washington, D.C., but the whole national tourism industry has seen a decline based on many things, whether it’s the threat level, whether it’s war, or the economy — they’ve all been affecting the tourism economy.”

With the war in Iraq over and the terror alert lowered to yellow, restaurants, tour services and hotels report that business has improved but is still below pre-attack levels.

“The fear factor is sort of declining,” said Thomas B. Whitley, of the Guild of Professional Tour Guides of Washington, D.C., which represents 300 guides. Whitley estimated business has doubled since last year.

The hotel occupancy rate has risen slightly from a 2001 low of 66.7 percent. Nearly 80 percent of the downtown area’s estimated 27,000 hotel rooms were booked the first week of June, up over the same period last year, according to the WCTC.

The Smithsonian Institution’s 16 museums still are not seeing pre-Sept. 11 visitor numbers, although the National Air and Space Museum is nearly there, spokeswoman Mary Combs said.