(CNN) -- On the morning of July 7, 2005, Islamic extremists detonated three bombs on trains and a bus across London, killing 52 people and wounding hundreds.
That night, U2 performed at a stadium in Berlin, where during "Sunday Bloody Sunday," frontman Bono donned a headband bearing the word "Coexist," designed to incorporate a Christian cross, a star of David and an Islamic crescent.
"Jesus, Jew, Mohammad, it's true. All sons of Abraham," he chanted, pointing to the symbols to plead for religious tolerance during a time of war -- a gesture Bono repeated throughout the tour.
