Among other of Mr. Bradbury's widely known works were "The Martian Chronicles, " "The Illustrated Man, " both short-story collections, and "Something Wicked This Way Comes, " a novel.

WSJ: Ray Bradbury, author of Classic 'Fahrenheit 451,' Dies at 91

Mr Obama later visited the Yad Vashem Holocaust memorial, which he said illustrated the depravity to which man could sink but also served as a reminder of the "righteous among nations who refused to be bystanders".

BBC: Obama tours symbolic sites in Israel and West Bank

But the experiences of one eight-man team illustrated how the courage and reputation of the elite force could not guarantee success.

BBC: Profile: The SAS