A Russia-backed rebel looks at the flag covered body of an Ukrainian serviceman in Debaltseve, Ukraine, February 20, 2015. The struggle for the strategic rail hub, Debaltseve, a sleepy town with a pre-war population of 25,000 people, left the town in ruins and became one of the darkest pages in the ongoing conflict in eastern Ukraine, which has already killed more than 6,000 people. (Photo by Vadim Ghirda/AP Photo/File)

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)

A nurse helps an injured bomb victim sitting at the back of a pickup truck at the Asokoro General Hospital in Abuja, April 14, 2014. A morning rush-hour bomb killed at least 35 people at a Nigerian bus station near the capital on Monday, raising concerns about the spread of an Islamist insurgency after the first such attack on Abuja for two years. Suspicion fell on Boko Haram, though there was no immediate claim of responsibility from the Islamist group mainly active in the northeast. Five hours after the blast, officials had given no death toll. Reuters journalists counted at least 35 bodies. (Photo by Afolabi Sotunde/Reuters)

Villagers cry for their relatives who were killed in an earthquake during a funeral in Longmen village, in Lushan county in southwest China's Sichuan province, on April 21, 2013. Rescuers and relief teams struggled to rush supplies into the rural hills of the area after an earthquake left at least 180 people dead and more than 11,000 injured. (Photo by Associated Press)

A person drags a suitcase as a boy clings to it on a square in front of a railway station ahead of the Chinese Lunar New Year in Qingdao, Shandong province, January 28, 2014. About 3.62 billion trips will be made during the 40-day Spring Festival travel rush, which started from January 16, reported Xinhua News Agency citing a government official. (Photo by Reuters/China Daily)

An Indian Air Force person walks carrying a Nepalese child, wounded in Saturday's earthquake, to a waiting ambulance as the mother rushes to join after they were evacuated from a remote area at the airport in Kathmandu, Nepal, Monday, April 27, 2015. The death toll from Nepal's earthquake is expected to rise depended largely on the condition of vulnerable mountain villages that rescue workers were still struggling to reach two days after the disaster. (Photo by Altaf Qadri/AP Photo)

People are seen at Avalon Beach on December 18, 2020 in Sydney, Australia. A cluster of Covid-19 cases on the northern beaches of Sydney has grown to 28, prompting NSW health officials to urge residents of affected suburbs to stay home. Traffic at Sydney Airport has increased as people rush to leave the city with several states imposing quarantine restrictions for New South Wales residents. (Photo by Jenny Evans/Getty Images)