Dozens of firefighters and police officers descended yesterday on Crystal City, but few people seemed fazed by the rescue vehicles piling up outside Jefferson Plaza One.

Runners jogged by without so much as an inquiring tilt of the head.

Movers unloaded two eighteen-wheelers just feet away without stopping to ask why the emergency crews had arrived.

Even a letter carrier continued his rounds, oblivious to the disruption.

"Typical D.C.," said Steve Snipes, director of management for the military at Jefferson Plaza One.

The scene might have caused a stir just about anywhere else in America. But not in the Washington area, where anti-terrorism drills have become a staple of the urban landscape since Sept. 11, 2001.

Four drills were staged nearly simultaneously -- two in Crystal City, two at the Pentagon -- to hone the region's emergency response capabilities.

Dubbed Gallant Fox III, the exercise was the third such exercise at the Pentagon since Sept. 11.

They enable the Pentagon Force Protection Agency and its federal, state and local response partners to evaluate existing plans and interagency coordination in the face of multiple threats.

As exercises go, this was relatively large. In all, there were about 900 participants, including volunteers provided by the American Red Cross to play the role of victims.

About 11:15 a.m., rescue workers began racing to the high-rise office building in Crystal City for a mock disaster.

The scene was already set: A suspicious vehicle was spotted outside the building, but before managers could completely evacuate, a bomb detonated, killing 450 people inside.

Hoses were connected to hydrants, victims were tagged and triaged on the lawn and commanders conferred in the middle of Crystal Drive and gave rapid-fire orders to turn off water mains and evacuate the wounded.

Throughout the two-hour exercise, workers strolling to and from lunch just kept on strolling, more concerned about finding shade in the heat than they were about the five firetrucks, lights flashing, parked askew on the street.

It might have been a testament to how well the emergency exercise was publicized to minimize alarm -- fliers were widely distributed in advance in Crystal City, and signs were posted by the Virginia State Police.

Or maybe it just takes a lot to rattle those who work in the shadow of the Pentagon and still vividly remember what a real terrorist attack looks like.

While the drills are hardly lifelike -- firefighters yesterday neither entered the building nor kept on their heavy coats when the afternoon heat got too intense -- officials said the exercises are a vital part of creating an integrated network of responders who can effectively communicate and work as a team.

The goal is to avoid "what we saw at the World Trade Center," said Ryan Broughton, a designated observer and controller at the Crystal City drill. "Here, police are integrated. Everyone is on the same page."

Communication lapses in the face of potential terrorist threats have continued to make headlines since Sept. 11, despite efforts to improve emergency response.

D.C. police officials, for example, had no idea that fighter jets and helicopters were being deployed over Washington to intercept an errant plane last month, even though they had a sergeant in the federal Homeland Security command center and the ability at their own headquarters to monitor what was taking place.

John Jester, director of the Pentagon Force Protection Agency, said the drills are all about being on top of the game, in this case, managing resources when faced with more than one attack.

Data collected from the drills will be analyzed and used to tweak procedures.

"The more you do this, the better the plans are," Jester said. "You can't just write a plan. You have to test it."

Lt. John Pignataro, left, and Keith Byrd, D.C. firefighters from Engine 16, lead two mock victims from the simulated bombing site. Workers walk past volunteers Cathryn Pelkey, lying down, and Kate Perek, portraying patients.