Ukrainian state emblem is seen on a gun's holster as soldiers guard naval base in the village of Novoozernoye, some 91 km west of Crimean capital Simferopol, Ukraine, on Monday, March 3, 2014. Ukraine says Russian forces controlling the strategic region of Crimea are demanding that the crew of two Ukrainian warships in Sevastopol's harbor must surrender. (Photo by Ivan Sekretarev/AP Photo)

An E.T. doll is seen while construction workers prepare to dig into a landfill in Alamogordo, N.M., Saturday, April 26, 2014. Producers of a documentary are digging in the landfill in search of millions of cartridges of the Atari “E.T. The Extra-Terrestrial” game that has been called the worst game in the history of videogaming. A New York Times article from 1983 reported that Atari cartridges of “E.T. The Extraterrestrial” were dumped in the landfill in Alamogordo. (Photo by Juan Carlos Llorca/AP Photo)

A participant takes part in the Bristol Park and Slide project, an interactive temporary installation by artist Luke Jerram set up in Park Street in the centre of Bristol, southwest England on May 4, 2014. Over 95,000 people applied for just 360 tickets to slide on inflatable lilos down a lubricated water slide in a town centre street. (Photo by Leon Neal/AFP Photo)

A policeman looks at a car crushed underneath a collapsed bridge in Belo Horizonte, Brazil, Thursday, July 3, 2014. The overpass under construction collapsed Thursday in the Brazilian World Cup host city. The incident took place on a main avenue, the expansion of which was part of the World Cup infrastructure plan but, like most urban mobility projects related to the Cup, was not finished on time for the event. (Photo by Victor R. Caivano/AP Photo)

Chinese rescuers carry an injuried resident after an earthquake hit an area of Ludian county in Zhaotong in southwest China's Yunnan province on August 3, 2014. At least 300 people were killed and 1,300 injured after a strong earthquake hit southwest China's mountainous Yunnan province, state media said. The quake in Zhaotong prefecture, in the province's northeast, toppled buildings and left residents frantically searching for survivors beneath the rubble, images on social media showed. (Photo by AFP Photo)

Damaged vehicles sit on Yeongjong Bridge in Incheon, South Korea, Wednesday, February 11, 2015. Two people were killed and at least 42 were injured on Wednesday after a pileup involving about 100 vehicles in foggy weather on the bridge near the Incheon International Airport, South Korean officials said. (Photo by Suh Myung-gon/AP Photo/Yonhap)

Bosnian men urge their horses to pull logs up a hill during a competition in the Bosnian town of Sokolac 50 kms west of Sarajevo, Bosnia,on Monday, April, 13, 2015. The annual festival celebrates the centuries old tradition of pulling logs honoring the owners of the strongest horses. Owners of the horses gather from all over Bosnia and beyond, and compete in a show of horse strength. (Photo by Amel Emric/AP Photo)

This artist image released from Japan's airline All Nippon Airways (ANA) on April 17, 2015 shows ANA's Boeing 787-9 aircraft into the colors of R2-D2 robot of Star Wars. Japanese air carrier ANA will place the special colored jetliner in service in this autumn. (Photo by AFP Photo/All Nippon Airways)