Russia-backed separatists stand at the site of the crashed Malaysia Airlines Flight 17 plane, near the village of Hrabove, eastern Ukraine, Thursday, July 16, 2015. The fighters said they have arrived to protect the media and make sure the MH17 crash site is clear of ammunition and mines. A year since a Malaysia Airlines Boeing 777 was blown out of the sky over war-ravaged eastern Ukraine, killing 298 people, there has been little official word of progress in determining what brought down Flight MH17. (Photo by Antoine E. R. Delaunay/AP Photo)

Men cover their heads from the sun while riding on a motorcycle during a hot day in Cairo, Egypt, August 17, 2015. A heatwave killed at least 61 people across Egypt from Sunday to Tuesday and caused nearly 600 people to be admitted to hospital, Egypt's health ministry said on state news agency MENA on Wednesday. (Photo by Amr Abdallah Dalsh/Reuters)

A drone operated by paramilitary police flies over the site of last week's explosions at Binhai new district in Tianjin, China, August 17, 2015. Many operations have resumed at China's Tianjin port, trade sources said, after explosions last week that killed more than 100 people and disrupted business at what is an important oil, gas and bulk import harbor for Asia's biggest economy. The explosions on August 12 led to the disruption of all chemical and oil tanker discharges at the port, and imports of iron ore were also affected. (Photo by Kim Kyung-Hoon/Reuters)

In this Monday, March 16, 2015 photo, Syrian refugee Samira Helal, 17, who is two months pregnant, poses for a portrait at inside her tent at an informal tented settlement near the Syrian border, on the outskirts of Mafraq, Jordan. Nearly 3.8 million Syrians have fled their country and are now registered as refugees, according to the U.N. Most face increasingly desperate circumstances. (Photo by Muhammed Muheisen/AP Photo)

Female Naval Academy plebes perform push ups with a twelve foot log on top of them during the annual Sea Trials May 17, 2016 at the Naval Academy in Annapolis, Maryland. The Naval Academy freshman class endures 14 hours of rigorous physical and mental challenges during the annual Sea Trials training exercise as part of the culmination of their freshman year at the academy. (Photo by Win McNamee/Getty Images)

As the sun rises, Gentoo penguins start their day on Wednesday, February 17, 2016, on Sea Lion Island, Falkland Islands. Sea Lion Island, which lies about 10 miles to the south of mainland East Falkland, is the southern most human-inhabited island of the more than 750 islands and islets of the Falkland Islands. (Photo by Jahi Chikwendiu/The Washington Post)

This computer image provided Monday March 17, 2014 by the Press Office of socialist candidate to Paris Mayor Anne Hidalgo, shows a tunnel of abandoned railway from the 19th century, now ramshackle and overgrown, turned into a cinema. Hidalgo’s plan envisions not just a green space but in the tunnels, places for farming fish and mushrooms. (Photo by AP Photo/Anne Hidalgo's Press Office)

Medics help a rescued miner after an explosion and fire at a coal mine killed at least 17 miners and left up to 300 workers trapped underground, in Soma, in western Turkey, Tuesday, May 13, 2014, a Turkish official said. Twenty people were rescued from the mine but one later died in the hospital, Soma administrator Mehmet Bahattin Atci told reporters. The town is 250 kilometers (155 miles) south of Istanbul. The death toll was expected to rise. (Photo by AP Photo/Depo Photos)