A journalist takes photographs at the site of Thursday's Malaysia Airlines Boeing 777 plane crash near the settlement of Grabovo, in the Donetsk region July 18, 2014. World leaders demanded an international investigation into the shooting down of Malaysia Airlines Flight MH17 with 298 people on board over eastern Ukraine, as Kiev and Moscow blamed each other for a tragedy that stoked tensions between Russia and the West. (Photo by Maxim Zmeyev/Reuters)

This picture taken on January 25, 2015 shows a participant taking part in an ice water challenge in Zhangjiajie, central China's Hunan province. Participants were required to stay in an ice pond, holding an ice block while eating ice-cream with an electric fan blowing at them. (Photo by AFP Photo/Stringer)

Participants of the the goth festival “Wave Gothic Festival” walk in fancy costumes along the festival area in Leipzig, central Germany, Saturday, May 23, 2015. About 20,000 members of the scene are expected to attend one of the world's largest gothic and “dark” culture festivals until May 25, 2015. (Photo by Jens Meyer/AP Photo)

A picturesque supercell formation in the northwest of Booker, Texas from June 2013. (Photo by Mike Olbinski/Barcroft Media)

Sunday night, Lauren Watts searches for her dog in Mayflower, Arkansas., after a tornado struck the town. (Photo by Benjamin Krain/The Arkansas Democrat-Gazette)

A man is silhouetted as he stands on a walkway in the sky lobby at the Chancellery, the seat of German Chancellor Angela Merkel (not pictured) in Berlin, May 7, 2014. (Photo by Thomas Peter/Reuters)

“Camille Lepage, a 26-year-old French photojournalist who had spent months documenting deadly conflict in Central African Republic has been killed, the French presidency said Tuesday, May 13. Lepage, a freelance photographer whose work was published in major French and American newspapers, died in western Central African Republic not far from the border with Cameroon, authorities said”. – Associated Press. Photo: Anti-balaka fighters from the town of Bossembele patrol in the Boeing district of Bangui, Central African Republic, February 24, 2014. (Photo by Camille Lepage/Reuters)

“Kilauea Rules”. The most extreme place we put ours kayakers to paddle till now. Photo location: Big Island, Hawaii. (Photo and caption by Alexandre Socci/National Geographic Photo Contest)