Surfers surf at Surf Snowdonia in Conwy, North Wales, September 3, 2015. The surf park, which cost $22.8 million, opened on August 1 and is the world's first commercial artificial surfing lake, according to the company.The pool is 300 metres (980 ft) long and 110 metres (360 ft) wide, containing a total of six million gallons of water. A bi-directional snowplough-shaped wave-generation mechanism, towed on a cable between the two central towers, moves up and down the pool on a three-rail track, generating the waves. (Photo by Andrew Yates/Reuters)

Chinese military medics take part in a parade commemorating the 70th anniversary of Japan's surrender during World War II held in front of Tiananmen Gate in Beijing, Thursday, September 3, 2015. (Photo by Ng Han Guan/AP Photo)

Star Wars fan Mike Deguzman practices with a toy lightsaber after purchasing some new toys that went on sale at midnight in advance of the film “Star Wars: The Force Awakens” in Times Square in the Manhattan borough of New York, September 4, 2015. (Photo by Carlo Allegri/Reuters)

Young migrants gesture during a day of solidarity organised by local organizations and resdients for asylum seekers at a makeshift camp outside the foreign office in Brussels, Belgium September 6, 2015. Over 150,000 people seeking to enter Europe have reached Hungary this year, most coming through the southern border with Serbia, and many apply for asylum but quickly try to leave for wealthier EU countries. (Photo by Yves Herman/Reuters)

In this handout provided by the National Aeronautics and Space Administration (NASA), SpaceX's Falcon 9 is moved to the launch pad prior to the rocket's Thales Alenia Space launch attempt on April 26, 2015 in Cape Canaveral, Florida. (Photo by NASA via Getty Images)

In this November 12, 2015, file photo, Mt. Everest is seen from the way to Kalapatthar in Nepal. An American climber has died near the summit of Mount Everest and an Indian climber is missing after heading down from the mountain following a successful ascent, expedition organizers said Sunday. (Photo by Tashi Sherpa/AP Photo)

Documentary photographer William E. Crawford was one of the first Western photographers to gain access to North Vietnam after the war ended. He has photographed the capital, Hanoi, at regular intervals since 1985, concentrating on the colonial and indigenous architecture, urban details, landscapes and intimate portraits of people in their home settings, street scenes and the city’s surrounding countryside. Here: 54 Hàng Ga (Chicken Street), 1994. (Photo by William E. Crawford from the book “Hanoi Streets 1985-2015: In the Years of Forgetting”)

Sam Warren climbs in to a prototype combat vehicle during the PrepperCon expo Friday, April 24, 2015, in Sandy, Utah. Hundreds of survivalists and “preppers” are gathering in the Salt Lake City suburb of Sandy for the first annual PrepperCon, featuring demonstrations of underground bunkers, food storage, and armored vehicles. (Photo by Rick Bowmer/AP Photo)