Children surround a man, left, that fell down while walking on a street suspected of having contracted the Ebola virus in the city of Monrovia, Liberia, Tuesday, August 19, 2014. The World Health Organization says the outbreak has killed more than 1,200 people, while authorities struggle to contain its spread and treat the sick. (Photo by Abbas Dulleh/AP Photo)

People pass by a vehicle almost completely submerged on a street covered with mud due to heavy floods in Tekija village September 17, 2014. One person died in Serbia and authorities scrambled to evacuate hundreds of people from villages threatened by rising rivers, officials said on Tuesday, in scenes recalling the devastating May flooding that killed dozens. (Photo by Djordje Kojadinovic/Reuters)

People gather at the site of a bomb explosion in Sanaa December 23, 2014. Five bombs exploded on Tuesday in Sanaa's old quarter, where many supporters of the Shi'ite Muslim Houthi group live, killing at least one person and wounding another, a Yemeni security official said. No one has claimed responsibility for the attacks, but the Houthis have been fighting the Sunni Islamist militant al Qaeda group and allied tribesmen since its gunmen captured Sanaa in September and forced the resignation of a government they had long seen as corrupt. (Photo by Khaled Abdullah/Reuters)

Law enforcement officers stand, with some turning their backs, as New York City Mayor Bill de Blasio speaks on a monitor outside the funeral for NYPD officer Wenjian Liu in the Brooklyn borough of New York January 4, 2015. Tens of thousands of law enforcement officers from across the country gathered on Sunday for the funeral of the second of two New York City policemen killed last month in an ambush that galvanized critics of Mayor de Blasio. (Photo by Shannon Stapleton/Reuters)

A woman cries while sitting on a road amid the destroyed city of Natori, Miyagi Prefecture in northern Japan March 13, 2011, after a massive earthquake and tsunami. Five years on from the tsunami that triggered meltdowns at Japan's Fukushima nuclear plant, the page is anything but turned. A magnitude 9 earthquake and towering tsunami on March 11, 2011 killed nearly 16,000 people along Japan's northeastern coast and left more than 2,500 missing. The 10-metre (33-foot) tsunami swept away everything in its path, including houses, ships, cars and farm buildings. (Photo by Asahi Shimbun/Reuters)

A Kenyan Red Cross personnel and a volunteer console a relative of a victim, at the site of a building collapse in Nairobi, Kenya, Saturday, April 30, 2016. A six-story residential building in a low income area of the Kenyan capital collapsed Friday night under heavy rain and flooding, killing at least seven people and injuring over 100 others, Kenyan officials said. (Photo by Sayyid Abdul Azim/AP Photo)

Chief priest Gbenga Saala raises a cutlass to kill a dog during an annual prayer and sacrifice celebration of the iron god Ogun in Abuja, Nigeria, June 23, 2015. Every year worshippers offer a dog as sacrifice to Ogun, a traditional Nigerian deity, in hope of an auspicious year ahead. Taxi drivers, blacksmiths, panel beaters and mechanics – trades that depend on metal for their livelihood – pay homage to Ogun, led by high priest Gbenga Saala. As part of the ceremony, the priest pours the dog’s blood on symbols of these workers’ trade: keys, spanners and other tools piled up in a metal barrel. (Photo by Afolabi Sotunde/Reuters)

Members of the media film as a ranger performs a post mortem on the carcass of a rhino after it was killed for its horn by poachers at the Kruger national park in Mpumalanga province August 27, 2014. Rhino poachers in South Africa now risk giving themselves away when they shoot thanks to a high-tech, gunfire-detection system being piloted in the country's flagship Kruger National Park. The stakes are high, for rhinos are being slain in escalating numbers for their prized horns, alarming both conservationists and the government since wildlife in South Africa is an important tourist draw. (Photo by Siphiwe Sibeko/Reuters)