In this concrete-covered and monument-strewn city -- the country's central nervous system for analyzing terrorist attacks -- what seemed to distinguish those who were coming and going yesterday after the attacks across London was a strange sense of fearlessness tinged with fatalism.

A feeling of what-will-be-will-be.

It sounded like a spirit snatched from the American frontier. It sounded like pure attitude -- wrapped in a little fear.

"There's ultimately no protection against it," said the Rev. Christopher Begg, 55, who teaches the Old Testament at Catholic University and was awaiting a Metro train in Brookland. He was referring to the terrorist attacks that killed at least 37 and injured more than 700 in London. His voice was quite serene. "What can you do if something is inevitable?"

Katie Van Hoey is a 24-year-old paralegal. She knows her family wishes she lived elsewhere. "They don't particularly like me living in the nation's capital," she said, also awaiting a train in Brookland while two transit police officers traversed the platform, an example of yesterday's heightened security. "It won't change the way I travel around the city though," she said. Then she went back to reading the book in her hands, "Paradise Lost."

All across the city yesterday, families of tourists still queued up for their boat rides, their trolley car rides, their lockstep strides to feast their eyes on the treasures of the city.

"It's not 'War of the Worlds,' " said Allison Carr, visiting from Minnesota with her mother and sister. "It's a war of our world."

It sounded like innocence lost. She's 20 years old. And yesterday she just wanted to have fun in a city existing in very complex times. "We've seen bomb-sniffing dogs," she said, sounding as if she suddenly realized how far she was from her home outside St. Paul.

"I told 'em I'd protect them," said Pat Bottini, 20, who is Allison's boyfriend and is living here during the summer, working as an intern for Minnesota Rep. Mark Kennedy. "You're used to seeing security everywhere anyway."

Descending into the subway, Allison's mom, Marlene Carr, 44, said that she was involved in the planning of a trip to the nation's capital a few years ago but was still somewhat haunted by the then-recent sniper shootings. "I was to be the chaperon during that trip. But we canceled at the last minute. My husband said, 'I'm a gambling man, but not with my family.' "

Mom looked around the subway. It was midmorning, but the downtown station seemed strangely unpopulated. "Is this normal?" she asked. "Is it usually this quiet?"

Bottini offered reassurance, telling the Carrs there was plenty of security around. "We had an evacuation at the Capitol recently because of a plane flying overhead," he said. "So everybody's ready."

A voice came over the Metro loudspeaker: "If you hear anything suspicious, please let the station manager know."

"I like hearing that," Marlene Carr offered. Then she said: "But if my husband were here, he'd say, 'Take a taxi, not Metro.' "

Kristine Carr, 16, will be going into her junior year of high school this fall. Just days ago she was rocking while listening to her favorite bands on TV during the Live 8 concert. "I thought it was really cool they were trying to put an end to poverty. But now it's sad to know the terrorists are still out there. Trying to get at us."

The Carrs were determined to see the Smithsonian. But the worry hadn't left Marlene Carr's voice as she zoomed along inside Metro. "I don't want to change my plans," she said with determination. Then she added -- knowing the odds weren't good -- "I hope my husband hasn't seen the news yet."

Kristine sensed her mom might need a boost. "They want us to be scared!" she said. And onward they went, Pat holding Allison's hand, and Marlene Carr's face not quite as sunny as it might look under other circumstances.

Gwen Hillesheim, 52, was in Washington for a conference. She's from Chicago and works as an educational consultant. Yesterday she wanted everyone to buck up. She exhibited no fear, awaiting a train at a Metro station. "I love the Metro. I love D.C. Public transportation is a great thing. I was in D.C. for 9/11. This is a great place to be during scary times."

Yesterday's explosions happened an ocean away, and yet, the tremors seemed mighty close. The aftershocks. That feeling of gloom. That feeling of siege. That feeling of here-we-go-again.

Gemma Robson, 19, is from London but has been working this summer at Camp Tomahawk in Hedgesville, W.Va. Yesterday was her only day off during the week. "It's just weird," she said, referring to the events in Britain. "A year ago I was in London and was underground and there was a bomb scare." She says she doesn't take the train anymore in London. But there she stood, inside the Metro system. Her boyfriend, Donovan Barrett, 26, tried to comfort her. "If something is going to happen, no one can stop it," he said. Robson looked up toward the ceiling, as if something might fall.

It was Donna Harris, a 27-year-old camp counselor from Ontario, who persuaded the group to come into Washington yesterday. "My mom called me and told me what happened," she said of the attacks in London. I said, 'Oh, that's just great.' So, I know, we're taking our chances."

There was a baseball game yesterday, the Mets and the Nationals. Robert O'Keefe, 57, had come down from New York to see his team. "It's been a sobering reminder," he said of the attacks. "You would have thought by now that London, New York, D.C. wouldn't be susceptible now with all the security. I got up this morning and went to the tourist attractions here. I was a little apprehensive, I'll admit, though, about taking the Metro."

But he said he squared his shoulders. He said he has seen a lot of inexplicable things in his lifetime. "I'm a New Yorker," he said, and hustled brightly off to his baseball game.

Riders pack a subway train at Metro Center under the watchful eyes of a transit police officer.

A Metro Transit Police officer patrols the Metro Center platform with a bomb-sniffing dog as part of the beefed-up security.