http://www.bbc.co.uk/news/live/uk-39355505
It's been horrible seeing the news report coming in. It now appears that this was a lone "madman" possibly with some twisted kind of terrorist agenda. I don't think using a car to kill innocent women and children pedestrains, as they walked along Westminster Bridge, will do anything but illustrate the insanity of their actions.
From eye witness accounts Police and Ambulance crews arrived rapidly, and the lives of most of those injured, seem to have been saved. After the attacker left his car, he was approached by an unarmed police officer. They challenged him and the officer was stabbed, sadly later dying from his injuries. Two armed police officers rapidly chased him on foot, shouted a warning, then shot him when he ignored it.
Even in those circumstances, they summoned medical help, and tried to save the attackers life. He died. Whilst it is sickening news, for a large open city, London is a very safe place. It is well supported by emegency services, medical and police. The police who are armed, are very highly trained. The contingency plans in place were quickly enacted, the area was rapidly placed in lockdown.
That area of London has many police, with substantial numbers armed, due to the proximity of parliament. There is no way to eliminate all risk in a free society, but I think the reports all seem to show that the response was very professional. But a truly horrible thing to see on the news.