Iraqi firefighters try to stop the fire of burning oil wells in Kirkuk, northern Iraq, 02 June 2016. Two Khabbaz oil field wells in Kirkuk Province, northern Iraq, exploded by suspected insurgents, a security official said. (Photo by EPA/Stringer)

Brush and trees are engulfed in flames after firefighters set a backburn along Highway 191 in an attempt to control a raging wildfire on June 10, 2011 in Nutrioso, Arizona. The fire, which is five percent contained, has so far consumed over 400,000 acres of land and destroyed 29 homes. (Photo by Kevork Djansezian/Getty Images)

Pfc. Sebastian Rodriguez, machine gunner, Weapons Platoon, Lima Company, 3rd Battalion, 3rd Marine Regiment, Marine Rotational Force – Darwin, fires an M240 machine gun during a night squad-attack exercise, here, May 22, 2013. (Photo by Sgt. Sarah Fiocco/U.S. Marines)

A C-17 Globemaster III crew prepares an air refueling mission September 27, 2012, at Joint Base Charleston, S.C. (Photo by Airman 1st Class Matthew J. Bruch/U.S. Air Force photo)

Paris authorities began draining the Canal Saint-Martin, a popular waterway that attracts tourists and revelers in the French capital's trendy northeastern 10th arrondissement, for the first time in 14 years, Paris, January 5, 2016. (Photo by Christophe Geyres/SIPA Press/Newscom)

Alfred the frog looks almost as scary as the pumpkin he is perched on at London Zoo 26 October 2011. Keepers at the zoo have joined in the Halloween tradition by supplying pumpkin lunches to some of their animals, including the giant waxy monkey frog. However Alfred is not quite the giant figure his species name suggests – he actually measures up at around 4 inches (10 centimeters). (Photo by EPA/Zoological Society of London)

Athlets run during the women's 3000 meter steeplechase at the International Athletics Meeting in Lucerne, Switzerland, 14 June 2016. (Photo by Alexandra Wey/EPA)