A German contestant adjusts his helmet during the “Battle of Nations” in Aigues-Mortes, southern France, Friday, May 10, 2013 where Middle Ages fans attend the historical medieval battle competition. The championship will be attended by 22 national teams, which is twice the number it was last year. The battle lasts until May 12. (Photo by Philippe Farjon/AP Photo)

A driver competes in his tractor during the Tractor Pulling Euro Championships in the western German town of Fuechtorf September 9, 2012. Eighty teams from across Europe participated in the two-day competition where high-powered tractor prototypes must pull a trailer down a 100-metre (328 ft) track as far as possible. (Photo by Ina Fassbender/Reuters)

A undated handout image provided by the Bochum University of Applied Sciences (Hochschule Bochum) on 04 October 2013 shows the German team Bochum's Cruiser class solar car during a test drive in the Northern Territoty, Australia, 16 September 2013. The Dutch vehicle is competing in the World Solar Challenge, driving from Darwin to Adelaide starting on 06 October 2013. (Photo by Hochschule Bochum/EPA)

David Guttenfelder was born in Iowa and graduated from the University of Iowa with a Bachelor of Arts in cultural anthropology. He has worked for the AP since 1994 based in Kenya, the Ivory Coast, India and Japan. He is currently AP’s chief Asia photographer and his feature work has been used prominently in editorial publications throughout the world including Time and National Geographic. Photo: U.S. soldiers from the 2nd Battalion, 12th Infantry Regiment, 4th Brigade Combat Team, fire mortars at known enemy firing positions from a base in the Pech River Valley in Afghanistan's Kunar province, Saturday, October 24, 2009. (Photo by David Guttenfelder/AP Photo)

Israeli soldiers play the parts of wounded civilians during a drill simulating a toxic spill from an attack on a train in Beersheba, southern Israel, 13 January 2016, as Home Front medical teams, fire fighters and police carry out rescue operations. The large scale drill is the concluding exercise of the Fourth International Conference on Healthcare System Preparedness and Response to Emergencies and Disasters and includes some 200 of the world's experts on health system readiness from around the world. The conference is dealing with all types of medical emergencies from terrorist attacks to natural disasters. (Photo by Jim Hollander/EPA)

A flight attendant wearing a Brazil soccer team jersey demonstrates the emergency mask on an airplane travelling from Kunming to Hangzhou June 23, 2014. A Chinese airline company renovated the cabin of one of its flights then dressed the flight attendants with soccer jerseys as a way to celebrate the 2014 Brazil World Cup and hoping to attract more customers, local media reported. (Photo by Wong Campion/Reuters)

79 year old Constance Ngubane spars in the ring as she takes part in a “Boxing Gogos” (Grannies) training session hosted by the A Team Gym in Cosmo City in Johannesburg on September 19, 2017. The grandmothers, many of whom are over 70 have been training with coach Claude Maphosa and claim that they no longer suffer from the ailments they had before, and are stronger than ever. The grannies travel from all over Cosmo City for the twice weekly sessions. Coach Maphosa is in the process of planning events in other areas for grannies who have been inspired by the story, to join in. (Photo by Gulshan Khan/AFP Photo)

Anna Sloan and Vicki Adams of Britain sweep during a match against Olympic Athletes from Russia in Session 1 of the Women' s Round Robin curling competition at the 2018 Winter Olympic Games at Gangneung Curling Centre in Gangneung, South Korea on February 14, 2018. The British team won the match convincingly, 10-3. (Photo by Cathal McNaughton/Reuters)