U.S. Park Police work to keep people away from the area surrounding the Washington Monument after a 5.8 magnitude earthquake struck the east coast August 23, 2011 in Washington, DC. Police officers said that unidentified material had fallen off the Washington Monument as a result of the earthquake. All the monuments and buildings along the National Mall have been evacuated and closed. (Photo by Chip Somodevilla/Getty Images)

A feeder trains a Siberian tiger cub at Erdaohe Tiger Park July 2, 2006 in Antu County of Yanbian Chaoxian Autonomous Prefecture, Jilin Province, China. About 15 artificially-fed Siberian tigers from Harbin Siberian Tiger Park are being trained to develop their ability to live in the wild. The wild Siberian tiger is listed as one of the most endangered species in the world, with its existing number estimated at around 400 worldwide, mainly in the northeastern part of China and the Far East of Russia. Reportedly there are more than 1,300 Siberian tigers which have been raised in China. (Photo by China Photos/Getty Images)

Stephen McDonagh takes part in the Irish Bog Snorkelling championship at Peatlands Park on July 27, 2014 in Dungannon, Northern Ireland. The annual event sees male and female competitors swim the 60m length of the bog watched by scores of spectators and takes place on International Bog Day. (Photo by Charles McQuillan/Getty Images)

Cars are parked near Place de la Concorde on March 12, 2014 in Paris, France. Inset: World War I, German airplanes at Place de la Concorde in Paris, wrecked by celebrating crowds on the day of the restoration of Alsace-Lorraine, November 18, 1918. (Photo by Peter Macdiarmid/Getty Images)

Giant panda Jia Jia enjoys her birthday cake made with ice and vegetables at Ocean Park in Hong Kong, Tuesday, July 28, 2015 as she celebrates her 37-year-old birthday. Jia Jia broke the Guinness World Records title for “Oldest Panda Living in Captivity” on Tuesday. (Photo by Kin Cheung/AP Photo)

A reveller parades on stage at the annual Trinidad and Tobago Red Cross Society's Children's Carnival Competition at the Queen's Park Savannah in Port-Of-Spain February 7, 2015. (Photo by Andrea De Silva/Reuters)

Women practice yoga during a performance on a glass bridge at the Shiniuzhai National Geo-park in Pingjiang county, Hunan province, China, November 5, 2015. About hundred yoga fans put on the show to promote the concept of green life and the idea of harmony between human and nature on Thursday, according to local media. (Photo by Reuters/China Daily)

An agent of the OIPR, one of the government agencies charged with managing protected land, stands next to cocoa trees inside Mont Peko National Park in Duekoue department, western Ivory Coast August 18, 2015. (Photo by Luc Gnago/Reuters)