Over 30 Douglas C-47 Skytrains (Dakotas) making final preparations for flight formation practice before the 75th D-Day Anniversary flight to Normandy in Duxford, England on June 4, 2019. (Photo by UK Air Force Images)

Alex Plunkett, left, and Sean Hart, both of Arlington, Va., join hundreds participating in the annual International Pillow Fight Day on April 5. Massive pillow fights broke out on the Mall in Washington and in cities around the world. (Photo by Marvin Joseph/The Washington Post)

A woman falls while slipping on ice during freezing rain on Roosevelt Island, a borough of Manhattan, in New York January 5, 2014. New York City was hit on Friday by the first severe winter storm of 2014 and was still in the grip of sub-freezing weather on Sunday morning. The woman got up and walked away from the fall. (Photo by Zoran Milich/Reuters)

Typhoon Bopha moves toward the Philippines, observed from the ISS, on December 2, 2012. (Photo by AP Photo/NASA via The Atlantic)

A woman takes pictures as Britain driver Lewis Hamilton steers his Mercedes during the third free practice at the Monaco racetrack, in Monaco, Saturday, May 26, 2018. The Formula one race will be held on Sunday. (Photo by Luca Bruno/AP Photo)

Flames from the County fire burn above Cache Creek Casino Resort on Saturday, June 30, 2018, in Capay, Calif. (Photo by Noah Berger/AP Photo)

Mr. Zhong Hua, of Johns Hopkins University School of Medicine, took this image of the peripheral nerves (those outside of the brain) in an 11.5-day-old mouse embryo, magnified five times. (Photo by Zhong Hua)

Models blow kisses backstage at the Red Beard show during MBFWI presented by American Express Fall/Winter 2014 on March 13, 2014 in Istanbul, Turkey. (Photo by S. Alemdar/Getty Images for IMG)