The bomb blasts in London remind me how perilous our world is these days. I recognize well many of the sites pictured on the BBC web site. I have taken the Underground from Kings Cross and Russell Square stations many times, and have been on the lines affected. The photos of the bombed bus at Tavistock Square are astonishing–the comparison of one eyewitness to the bursting of a sardine can was apt.

The question for all time: What kind of hatred causes someone to want to kill innocent people who have nothing to do with any political process or decision-making?