Almost two days after the killing of Drummer Lee Rigby the sense of shock has not abated, and many of the questions are still unanswered.
The immediate reaction of the vast majority of people is to express sympathy with the family of the young soldier in the aftermath of this murder most foul
There have been heartfelt messages from people of every background, and the family has expressed its appreciation of the support of so many people in the midst of its loss. That grief will continue, and among the wider community there remains a sense of great unease that a young soldier can be hacked to death in London in broad daylight.
Lee Rigby's death also raises many fundamental questions about the balance between effective security and also the basic freedoms in a democratic society. Questions are being asked about why people known to security forces were not thought to be dangerous enough to warrant their arrests before their hate-filled statements led to something much more sinister.
However, the Communities Secretary Eric Pickles made an important point when he said that security experts told him of the difficulty of controlling people for the greater good of all, yet within a free society.
Although the security forces have been successful in curbing many other threats before they have exploded into violence, even the best security systems in the world cannot deal with every possible contingency.
No doubt the political leaders and security chiefs will try to learn lessons from this appalling tragedy in their attempt to make the streets safer. Meanwhile, it is important to recognise that the London killing has been strongly condemned by Muslim leaders everywhere, including Dr Mazhar Khan of the Belfast Islamic Centre which was targeted by a paint bomb on Thursday night.
This is not a time for reprisals, but for people of all faiths and of none to stand together against violence in all its forms and recognise the positive influence of the vast majority of the Muslim people.