London's burning

Shocked to hear that bombs went off in London Madrid-style this morning. Am worried for my high-school mates who are living / travelling there; the bizarre thing is, London seems disturbingly and relatively unfretted, according to Chezzz who is holidaying there at the moment. Could it be that Londoners have seen it all? Could it be that after the 2nd World War air raids, IRA bombings in late 80's and early 90's, Neo-Nazi's bombings in Brick Lane, Londoners might have actually developed some sort of emotional immunity to terrorism and mass destruction? Even though the scale of this attack is a fraction of 9-11th's, New Yorkers / Americans in general strike me as a whole lot more paranoid and panicky whenever alerts come up.