The heavy metal rockers' performance in Salt Lake City was due to begin at 7pm local time, but fans were left waiting outside the auditorium for almost three hours until they were finally let in around 10pm.

Energy Solutions Arena's manager Zane Miller told Fox 13 News the delay was down to "unexpected technical problems", and frontman Vince Neil and bassist Nikki Sixx took to during those three hours to apologise.

Sixx writes, "Sorry for the delay. This building did 'not' have their act together today. We will have 100 per cent of our show later", while Neil adds, "Sorry Salt Lake for delay! Not our fault, we've been ready to rock for hours!..."

The band's farewell tour continues in Denver, Colorado on Friday (31Jul15).