For just the second time in the band's career, U2 canceled a show mid-set due to issues with Bono's voice. During the fourth song in the band's second Berlin show, "Red Flag Day," Bono lost his voice. The audience sang through the first chorus and second chorus as Bono tried to recover his voice in the verses. At the end of the song, Bono apologized, saying, "I think it's the (stage) smoke. I can promise you I have not been smoking, but this is like a giant cigar ... I've lost my voice and I don't know what to do."

Bono said he was "singing like a bird 10 minutes earlier" and joked that he didn't want to be one of those singers who demand perfect conditions to sing. He asked for the smoke machines to be turned off and the air conditioning to be turned on higher. He then attempted to sing "Beautiful Day." He fought his way through the song, with the audience singing along as loud as they could. At the end of "Beautiful Day," he apologized again and said they needed a 10- to 15-minute break to figure out what happened, also promising the band would do a make-up gig as a result. He told the audience if they wanted to leave it was OK, but they were going to do their best to get back on stage.

After a 40-minute break, an announcement was made that the show would not continue, and fans should hold on to their ticket stubs and watch social media for more announcements. An official announcement should be made on U2.com in the coming days regarding any possible rescheduling.

The last time U2 had to cancel a show mid-set was Dec. 18, 1989, in Amsterdam. The rest of the Amsterdam shows were postponed and moved to Rotterdam in January 1990.

See the full Berlin 2 set list.

Next up is Cologne, Germany, on Sept. 4.