The federal base-closing commission voted yesterday to close the storied Walter Reed Army Medical Center and move more than 20,000 defense jobs from leased office space in Northern Virginia to military bases.

The closure of Walter Reed carries considerable emotional freight in the District, and the Virginia office moves could bring tremendous change to the region's economy, traffic, pollution and lifestyles as thousands of workers relocate from transit-friendly sites in Arlington and Alexandria onto bases in outer suburbs.

"I don't know if it is possible or appropriate to move all employees of the Department of Defense onto DoD facilities," said Anthony J. Principi, the commission's chairman. "At the same time, I think the [defense] secretary should have the management ability to manage his people."

Virginia officials, who accused the commission of exceeding its legal mandate in considering the office shifts, expressed disappointment in a decision that could leave acres of vacant commercial space in Arlington.

"We continue to feel leased space was improperly targeted at the start of this process, and we will continue to work with our Congressional and local partners to explore our options," Gov. Mark R. Warner (D) said in a statement.

But he and others said they were pleased that the panel chose to leave two sets of valued military researchers in place in Arlington: the Office of Naval Research and the Defense Advanced Research Project Agency, which represent about 1,700 jobs and are the linchpin for as many as 4,000 private consulting jobs.

"That's the intellectual engine," said Rep. Thomas M. Davis III (R-Va.) "These are the areas that are generating the ideas. DARPA, for heaven's sake, invented the Internet."

Still, thousands more jobs would go beyond the Capital Beltway, some across the country, in a shift designed not only to save money but also to protect Defense workers from possible terrorist attacks.

The biggest destination in the region would be Fort Belvoir in Fairfax County, which could add as many as 18,000 jobs. Fort Meade in Anne Arundel County could pick up more than 5,000 positions, and Marine Corps Base Quantico in Prince William County would gain about 3,000, the Defense Base Closure and Realignment Commission said.

Maryland would gain 1,300 military and civilian jobs under a plan that would close Walter Reed and expand what is now the National Naval Medical Center to create a "world-class flagship facility" on the Bethesda campus. The facility, which would bear Reed's name, would have 340 hospital beds and care for the most critically injured troops.

"Kids coming back from Iraq and Afghanistan, all of them in harm's way, deserve to come back to 21st-century medical care," said Principi, a former Department of Veterans Affairs secretary.

In addition, a 140-bed community hospital would be built at Fort Belvoir to serve military families in Northern Virginia.

The base closure commission must submit its final report to President Bush by Sept. 8. The president can accept the list or send it back for revision before forwarding it to Congress, which must accept or reject the recommendations in full.

In other decisions yesterday, the commission approved most of the Pentagon's broader plan to merge hundreds of medical, training, finance, research and other support facilities into centers that would serve all military branches. On Wednesday, the panel spared key bases in New England and granted a reprieve to Oceana Naval Air Station in Virginia Beach.

Today's session will focus on several of the most contentious proposals, including efforts to close Ellsworth Air Force Base in South Dakota and Cannon Air Force Base in New Mexico as well as overhaul the Air National Guard.

As word of the Walter Reed decision spread, District officials said the community would mourn the passing of an institution that has been part of the nation's capital for nearly 100 years.

"I'm very, very disappointed," Mayor Anthony A. Williams (D) said. He added that the president clearly is not inclined to reverse the decision and save Walter Reed.

Williams and others said the next step is to determine what federal officials plan to do with the property. The mayor said he would be willing to entertain development of a federal center similar to one planned for the Department of Transportation along the Southeast waterfront. But D.C. Council Chairman Linda W. Cropp (D) and council member Adrian M. Fenty (D-Ward 4), who represents the area, argued that the city should move immediately to persuade federal officials to relinquish the property to the city.

"I really regret that they did close Walter Reed. But now we need to get control," Cropp said. "This is a major property in the heart of the District of Columbia."

The Walter Reed campus, which lies on 113 acres between Georgia Avenue and 16th Street in Northwest Washington, would be an attractive parcel for residential and commercial development, real estate experts said.

Del. Eleanor Holmes Norton (D-D.C.) cautioned city officials not to get too excited because it could easily take 10 years for Congress to fund the new hospital in Bethesda.

Even after Congress allocated the money, Norton said, the federal government would have to follow a complex procedure to find a new use for the land, starting by offering it to every federal agency. If none was interested, the District would have a shot, she said.

"The first thing people have got to do is to stop believing there's going to be any action anytime soon," Norton said. "It's obviously a prime piece of land. It's what's on the land that makes development difficult."

If the city gained control, Williams and others said, it would create an unprecedented opportunity to develop a neglected stretch of Georgia Avenue, add housing to a desirable neighborhood and plump up the tax base. As a federal installation, Walter Reed does not pay property taxes.

The Defense Department said the Walter Reed plans would have a one-time cost of $988.8 million and would save $301.2 million over 20 years. The Pentagon studied a plan to close the Bethesda hospital and move it to the Walter Reed campus, but it would have cost $400 million more, commission staff said.

The District could gain other positions if the Pentagon chose to consolidate medical commands at Bolling Air Force Base.

In Northern Virginia, the biggest effect of the closings would be the loss of more than 20,000 employees from leased office space, according to a study commissioned by Transwestern Commercial Services, a commercial real estate firm in Bethesda.

According to the Transwestern study, roughly 15,000 contractors working on $13 billion worth of contracts with the Defense Department could also follow their clients. The study included the 1,700 research jobs the panel chose not to move.

If the contractors leave, that would dump about 3 million square feet of office space back on the market, mostly in Crystal City. The move of several thousand workers to Fort Belvoir and Fort Meade, the study says, could add to gridlock.

The study estimates that 84,900 daily car trips would be added to the area's highways by 2015.

"It will take six hours for peak afternoon traffic to get through the Fairfax County Parkway at I-95 in 2010," said Stewart Schwartz, executive director of the Coalition for Smarter Growth. "It will take an estimated five hours to clear peak afternoon traffic from the Fort Belvoir area as a whole, even with already planned road expansion."

Commission members, who held their deliberations in a basement meeting room in a Crystal City hotel, know the Washington area well and could guess the sort of transportation challenges the moves could create. "Many of us have grappled with this issue since the very first time we saw the proposals," said James T. Hill, a commission member and retired Army general. He said his first concern was, "How are we all going to get into the gate at Belvoir?"

In Maryland, officials said job gains at the Bethesda hospital and Fort Meade would boost the economy, particularly the biotechnology sector.

"Because of the proximity of Walter Reed to Bethesda, I don't see a lot of upheaval," said Rep. Chris Van Hollen (D-Md.).

Aris Melissaratos, Maryland's secretary of business and economic development, said he was disappointed that the commission decided to leave the high-level researchers in Arlington. "I really wanted those," he said. "We're going to get them eventually."

The brisk pace that the commission had maintained during its first day of deliberations Wednesday slowed yesterday as members labored through an often complex series of proposals aimed at consolidating military support functions scattered across the country.

Although generally approving of the Pentagon's recommendations, the panel rejected a plan to consolidate Army aviation training by moving the logistics school at Fort Eustis, Va., to Alabama's Fort Rucker.

The commission also voted to save military finance offices in Cleveland; Limestone, Maine; and Rome, N.Y. And the commission pulled back from a merger that would have combined the Naval Postgraduate School in Monterey, Calif., with the Air Force Institute of Technology at Wright-Patterson Air Force Base near Dayton, Ohio.

Turning late in the day to the Air Force, the commission rejected a Pentagon proposal to remove all active-duty combat aircraft from Eielson Air Force Base in Alaska, but it voted to shut a smaller Alaskan airfield, Galena Airport Forward Operation Location. And it backed a Pentagon recommendation to close Onizuka Air Force Station in California.

Staff writers Bradley Graham, Dana Hedgpeth, Nelson Hernandez and Michael D. Shear contributed to this report.

Spec. Emmitt Courtney leaves Walter Reed Army Medical Center. News of the vote to close the hospital hit hard among its 5,630 workers. Story, A12.The Defense Base Closure and Realignment Commission votes to close Walter Reed Army Medical Center and move its services to the Bethesda home of the National Naval Medical Center.