Members of Saudi security forces take part in a military parade in preparation for the annual Haj pilgrimage in the holy city of Mecca September 17, 2015. (Photo by Ahmad Masood/Reuters)

John Klatt and the Air National Guard MXS (right) and Mike Wiskus and the Lucas Oil Pitts take to the skies at the Memphis Airshow, on Sat., September 26, 2016 in Millington, Tenn. (Photo by Brandon Dill/Invision for John Klatt Airshows, Inc./AP Images)

Andrej Ciesielski dangels his legs off the side of a building overlooking Times Square, New York City. (Photo by Andrej Ciesielski/Caters News Agency)

Japan Self-Defense Force (JSDF) soldiers and firefighters make rescue works among mountain lodges, covered with volcanic ash near the peak of Mt. Ontake, which straddles Nagano and Gifu prefectures in this September 28, 2014 photo taken and released by Kyodo. More than 30 people were feared dead on Sunday near the peak of the Japanese volcano that erupted a day earlier, sending a huge cloud of ash and rock tumbling down its slopes, while packed with hikers. (Photo by Reuters/Kyodo News)

A man holding a tray of belongings wades through a road at an area flooded by the Omoigawa river, caused by typhoon Etau in Oyama, Tochigi prefecture, Japan, in this photo taken by Kyodo September 10, 2015. (Photo by Reuters/Kyodo News)

Medic James E. Callahan of Pittsfield, Mass., gives mouth-to-mouth resuscitation to a dying soldier in war zone D, about 50 miles northeast of Saigon, June 17, 1967. Thirty-one men of the 1st Infantry Division were reported killed in the guerrilla ambush, with more than 100 wounded. (Photo by Henri Huet/AP Photo)

Ammunition airlift into besieged Khe Sanh, Operation Pegasus, April 1968. (Photo by Larry Burrows/AP Photo)

This Sunday, September 7, 2014 photo provided by Rachel Kirk shows smoke from a fire rising above Little Yosemite Valley near Yosemite National Park, Calif. (Photo by Rachel Kirk/AP Photo)