A weeping South Vietnamese mother and her three children are shown on the deck of this amphibious command ship being plucked out of Saigon by U.S. Marine helicopters in Vietnam, April 29, 1975. (Photo by AP Photo)

Belgian riot police officers are covered by hay and eggs thrown by demonstrators as farmers and dairy farmers from all over Europe take part in a demonstration outside an European Union farm ministers emergency meeting at the EU Council headquarters in Brussels, Belgium, September 7, 2015. Thousands of farmers gathered in the European capital calling for more help with low prices and high costs. (Photo by Jacky Naegelen/Reuters)

A model presents a creation by French designer Barbara Bui as part of her Spring/Summer 2016 women's ready-to-wear collection during Fashion Week in Paris, France, October 1, 2015. (Photo by Charles Platiau/Reuters)

The giant metal structure sits 330ft above the ground on the roof of a 22 storey office block in Dutch capital Amsterdam on September 6, 2016. Tourists sit in a playground-style chair as they propel themselves them over the edge of the building with only thin-air between them and the ground below. Engineers spent several years designing and building the breathtaking swing. By being fixed to the top of a building it reaches new heights – dwarfing other swings around Europe but trailing behind the 1,150ft high mechanical rides at the Stratosphere Hotel in Las Vegas, Nevada. (Photo by Huub Zeeman/SWNS.com)

Miss Universe contestant Desire Cordero, of Spain, poses for a photo after a news conference for contestants from Latin America and Spain, Monday, January 12, 2015, in Doral, Fla. The Miss Universe pageant will be held on January 25, in Miami. (Photo by Wilfredo Lee/AP Photo)

Elementary school children play outside their classrooms as mount Sinabung volcano spews thick volcanic ash in the background on February 10, 2017 in Karo, Indonesia. Mount Sinabung is one of the most active volcanoes in Indonesia and last erupted in May 2016, killing seven people. (Photo by Albert Damanik/Barcroft Images)

Men ride a motorcycle in front of destroyed houses after Hurricane Matthew passes Jeremie, Haiti, October 7, 2016. (Photo by Carlos Garcia Rawlins/Reuters)