Hot air balloons take to the skies over Bristol city centre on August 6, 2012 in Bristol, England. The early morning flight of over twenty balloons over the city was organised as a curtain raiser for the four-day Bristol International Balloon Fiesta which starts on Thursday. Now in its 34th year, the Bristol International Balloon Fiesta is Europe's largest annual hot air balloon event in the city that is seen by many balloonists as the home of modern ballooning. (Photo by Matt Cardy)

Vietnamese military personnel in traditional dress take part in a parade celebrating the 40th anniversary of the end of the Vietnam War which is also remembered as the fall of Saigon, in Ho Chi Minh City, Vietnam, Thursday, April 30, 2015. (Photo by Dita Alangkara/AP Photo)

A pro-democracy demonstrator fights with a Soviet soldier on top of a tank parked in front of the Russian Federation building on August 19, 1991, after a coup toppled Soviet President Mikhail Gorbachev. The same day, thousands in Moscow, Leningrad, and other cities answered Russian Republic President Boris Yeltsin's call to raise barricades against tanks and troops. (Dima Tanin/AFP/Getty Images)

The picturesque Zao Ski Resort, one of Japan's oldest and most popular ski destinations, is illuminated on February 10, 2007 in Yamagata Prefecture, Tohoku region of Honshu island, Japan. Coniferous trees such as the Aomori white fir lie covered with chrystallised ice and snow (described as “silver frost” or “snow monsters”) and attract visitors. (Photo by Koichi Kamoshida/Getty Images)

Sara Takanashi of Japan, Maja Vtic from Slovenia and Germany's Carina Vogt (R-L) prepare for a training session of the women's Individual normal hill HS100 ski jumping at the Nordic World Ski Championships in Falun February 18, 2015. (Photo by Kai Pfaffenbach/Reuters)

A model falls over on the runway during the SECCRY Hu Sheguang Collection 2014 Show during Mercedes-Benz China Fashion Week, March 30, 2014, in Beijing. (Photo by Lintao Zhang/Getty Images)

A man sits on the window of a burning building before falling from it, in central Lahore May 9, 2013. Fire erupted on the seventh floor of the LDA plaza in Lahore and quickly spread to higher floors leaving many people trapped inside the building. At least three people fell from the high floors trying to avoid fire that engulfed the building, local media reports. (Photo by Damir Sagolj/Reuters)