Libyan forces allied with the U.N.-backed government fire a shell at Islamic State fighters' positions in Sirte, Libya August 15, 2016. (Photo by Ismail Zitouny/Reuters)

Women play soccer as the Tungurahua volcano spews a column of ash during an eruption in Huambalo, Ecuador, Saturday, March 5, 2016. Tungurahua is 16,480 feet (5,023 meters) high and has been active since 1999. (Photo by Dolores Ochoa/AP Photo)

Dhruva Aliman does a back somersault as he dismounts from a slackline on the beach at Santa Monica, California on October 19, 2014. Slackline is a balance sport where a line of webbing is adjusted at different levels of tension between two anchor points and participants (called slackers) perform tricks and stunts including somersaults. (Photo by Mark Ralston/AFP Photo)

A woman offers prayers by a road as a rickshaw puller transports passengers in Kolkata October 28, 2014. (Photo by Rupak De Chowdhuri/Reuters)

Members of the Wasteland Warriors from the movie “MadMax” pose during the Wacken Open Air festival on August 4, 2016 in Wacken, Germany. Wacken is a village in northern Germany with a population of 1,800 that has hosted the annual festival, which attracts heavy metal fans from around the world, since 1990. (Photo by Alexander Koerner/Getty Images)

A woman and her dogs stop and look at a store mannequin wearing a dog's head mask outside a fashion shop in Nice, France, May 3, 2016. (Photo by Eric Gaillard/Reuters)

People dressed as zombies participate in a parade for World Zombie Day 2016 in London's West End, Britain on October 9, 2016. (Photo by Splash News and Pictures)

United States Coast Guard Academy Cadets Second Class Aurimas Juodka, left, and Sheila Bertrand get in the face of “swab” Kevin Lennox as Bravo Company finishes at the barber shop and mailroom during R-Day, the reporting-in day that marks the beginning of the 7-week “Swab Summer” for the class of 2018 Monday, June 30, 2014, in New London, Conn. About 250 prospective cadets, Swabs, start the program designed to indoctrinate them to the military life of the academy and at the end will be accepted into the corps of cadets. (Photo by Sean D. Elliot/AP Photo/The Day)