What strikes me, from the TV and net coverage, is that the emergency services really have planned how to react to such a horrible event, and that has kept the casualty figures low. Of course no plan survives contact with the Enemy, but in particular using the air ambulance to ferry doctors to the scene, rather than patients from it, seems a clever idea. Despite what one might expect, all the reports talk about how calm most people were, at least once they had managed to open train doors and windows.
It's all very well going on about unattended parcels, but a suicide bomber is not an unattended parcel. Channel 4 News speculated that the bus bomb might have been a bomber who was evacuated from the tube, which would make a certain amount of sense; though on the other hand, it would also be cunning to target a second form of transport after one had been closed down.
The bus bomb is curious for many ways. It gives the event a much more visual presence than all those mobile phone videos of - darkness. Without that, there wouldn't be the awful but striking images like 9/11 and the Madrid train bombings.
There is no way of avoiding these things. We can only be so vigilant. It's awful for the people involved, their families and loved ones - but for the rest of us, life must go on, and in as normal a fashion as possible, otherwise the terrorists win. The probability of being caught in such an incident is vanishingly small; that's of no comfort if it happens to you, of course.
I suspect many people who work in London will take tomorrow off work, and that is probably a reasonable thing to do - the public transport will be patchy. Let the experts do their job in recovering the infrastructure. We can't go about our business as if nothing has happened, but we should try.