On the surface, at least, just a day like any other.
But the apparent calm barely conceals the tension that still grips this city -- the streets may be packed but the Underground train system, which normally carries 3 million passengers a day, is scarcely half-full. It has never been easier to find a seat.
The security services, meanwhile, are honing their theories about who was responsible. Crispin Black, the director of Janusian Security Risk Management and an adviser on security affairs, told RFE/RL: "There are two competing theories at the moment and they both make sense. One is that they're [the bombers] homegrown British Muslims and we know that that has been the biggest worry for the government. But the leading theory at the moment isn't that -- there's general agreement in the analytical community that the finger is pointing much more to a North African connection."
And the reason for that, he says, is the resemblance between the high explosive used in the London attack and last year's Madrid explosions, in which a clear North African connection has since been established. That and the similar circumstances of the two cases -- coordinated, almost simultaneous attacks on highly vulnerable commuter-train travellers.
Crispin Black's office is just 100 meters from where one of the 7 July bombs blew the roof off the No. 30 double-decker bus, killing 13 and sending scores more to hospital. Today, like all the bomb sites, it is hidden from public view by giant screens, behind which teams of investigators are working day and night.
It is a frustratingly slow task but in one respect the investigators are fortunate. London has more closed-circuit television (CCTV) cameras watching its streets and public places than almost any other city in the world. Peter Fry, director of the British CCTV User Group, told RFE/RL: "They [the police] have already said that they have seized all the tapes that they feel are necessary. It is a well-rehearsed procedure that the moment that there is a major event, then the police officers will have a list, or have lists, of those with CCTV and will go around and seize those tapes."
The police are now poring over hundreds of thousands of hours of tapes -- but have yet to determine at which station or stations the bombers began their journey.
According to Brian Paddick, deputy assistant commissioner of the London Metropolitan Police, the public has a major role to play in helping the investigation.
"There have been over 1,700 telephone calls to the confidential antiterrorist hotline," Paddick said. "And we would urge anybody who feels that they have any information -- no matter how trivial -- to call that confidential hotline number. In addition, detectives today [10 July] have issued an urgent appeal for any photographs, video footage, or mobile-telephone images that were taken on the morning of Thursday, 7 July -- particularly in those areas close to where the four bombs exploded."
But the investigators fear they may be racing against time. The awful knowledge gnawing at the mind of anyone travelling or working or holidaying in London today is that the people who did it are still out there.
"Whether they are homegrown British Muslims or some sort of North African connection, they are still are large," Crispin Black said. "One of them may have died in the bus, in the bus bomb, but the other three are certainly still at large. When you look at how the IRA [Irish Republican Army] operated: a cell would retreat after carrying out an atrocity and lie low and make plans for the next hit."
It is a security service's nightmare: an unknown terrorist cell still in place, still armed and ready, perhaps, to strike again. London and its visitors have held their nerve so far. Another bomb might wreak more than physical havoc.
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