Thinking about London

[intertext]

Many years ago, I remember sitting on an underground train, reading a notice that said "if you see an unattended bag or package, do not touch it; report it immediately to authorities..." and not at first understanding until realizing that it referred to the possibility of a bomb. Londoners have had to deal with more than their share of terrorist attacks in the form of IRA bombs and so on - this one is "just one more"... but the worst, apparently, since WW2. My heart is with my compatriates, my family, my friends, anyone affected by this evil.