A woman falls while slipping on ice during freezing rain on Roosevelt Island, a borough of Manhattan, in New York January 5, 2014. New York City was hit on Friday by the first severe winter storm of 2014 and was still in the grip of sub-freezing weather on Sunday morning. The woman got up and walked away from the fall. (Photo by Zoran Milich/Reuters)

Breitling Wingwalker Freya Paterson, from Liverpool, UK, flies above Kuwait City's iconic Water Towers with pilots David Barrell and Martyn Carrington, on March 6, 2014. The team loop and roll up to 160 mph enduring G-forces of 4-5g. Crowds are expected to line the Kuwaiti coastline to catch a glimpse of the Wingwalking team on Saturday, March 8, 2014, to mark the opening of the first dedicated boutique in the city for the prestigious watch brand. (Photo by Katsuhiko Tokunaga/Breitling)

Soviet Army soldiers sit on their tanks in front of the Czechoslovak Radio station building in central Prague during the first day of Soviet-led invasion to then Czechoslovakia on August 21, 1968. (Photo by Libor Hajsky/Reuters)

Canada's Mandy Marchak (R) is taken down by France's Pauline Biscarat during the final match of the Hong Kong Sevens rugby women's invitational cup in Hong Kong March 28, 2014. (Photo by Tyrone Siu/Reuters)

Tourists take a “selfie” as demonstrators burn a trash container during a May Day rally in Barcelona, Spain, on May 1, 2014. Tens of thousands of workers marked May Day in European cities with a mix of anger and gloom over austerity measures imposed by leaders trying to contain the eurozone's intractable debt crisis. (Photo by Manu Fernandez/Associated Press)

Russian Police academy female cadets march during a rehearsal for the Victory Day military parade at Dvortsovaya (Palace) Square in St Petersburg, Russia, Wednesday, May 7, 2014. Victory Day, marking the defeat of Nazi Germany, is Russia's most important secular holiday celebrated on May 9. (Photo by Dmitry Lovetsky/AP Photo)

A stuntman performs in a car at the “Well of Death” at an exhibition in Srinagar, India, Friday, May 23, 2014. In the Well of Death, stunt drivers on motorbikes and cars drive in circles around the vertical walls of the well-shaped construction. (Photo by Dar Yasin/AP Photo)

Inês Carvalho (C), accompanied by her sister and cousin, is helped by her aunt to dress up at Alfama neighborhood in Lisbon on June 12, 2014. Carvalho, 18, is one of the revelers from the Alfama march and every Saint Anthony's day, Lisbon's protector, she parades with several other typical neighborhoods of the city. (Photo by Patricia De Melo Moreira/AFP Photo)