During the shoot U2 played an eight @-@ song set , which included four performances of " Where the Streets Have No Name " . Prior to filming , a week was spent reinforcing the roof of the liquor store to ensure it would not collapse if it were to be intruded by a group of fans . A backup generator was put on the roof so the shooting could continue in the event that the authorities shut off the power on the primary generator , which happened during filming .