I live in Madrid, Spain, and at this moment we are enjoying a (momentary?) respite from nearly 40 years of constant terrorist attacks, mostly by Basque separatists, with the one monumental attack by Al Qaeda in March 2004 with nearly 200 dead.
I remember once, many, many years ago, being in an office meeting and hearing through the open window a very close by, "ratatatatat" followed by a "boom", followed by the most total of silences, followed minutes later by sirens, which was the machine gun burst and grenade chaser that killed a Spanish admiral, the direct descendent of Christopher Columbus and his chauffeur, a poor recruit.
The daughter of a friend of ours lost an eye in an Eta bomb attack... she was just passing by.
The only consolation I can give the people of Boston is that if it goes on long enough, you finally get used to it... almost. DS