Rihanna takes the tube in London

Rihanna shocked commuters in the U.K. on Wednesday (05Oct11) by taking public transport to travel to her gig at London's O2 Arena.

The Umbrella hitmaker, who is currently touring Britain with her Loud shows, surprised onlookers as she stepped onto an underground tube train to travel through the capital to the concert venue.

One lucky fan who met Rihanna on the train posted a photo of the singer in the carriage on Twitter.com, alongside the words, "I met Rihanna on my way home, told her she was crazy for taking the tube she said 'Dunno how you guys do it'."

Rihanna responded to the female fan's message, writing back, "Word up!!!"