Possible Clues:

• German warning
• German word in a U2 album title
• Look out up in Berlin! Harry can't hug!
• Warning in Germany
• German crew loaded gun: look out!
• 'Watch out!' in Germany
• '-- Baby' (#1 U2 album of 1991)
• German warning!
• Caught frolicking around rear of hidden cave
• Essen exclamation