Gunfire was brought to the steps of President Truman's Washington home, Blair House, as two assassins tried to kill the chief executive, November 1, 1950. One of the gunmen, Oscar Collazzo of New York, lay wounded at the bottom of Blair House's front steps after the president's police guard had finished their work, at the cost of one guards' life, Dec. 9, 1950. The second gunman was killed. (Photo by Harvey Georges/AP Photo)

The Invasion. A quiet street in Macau. Modernization around is quickly changing the city, as documented by Paul Tsui. (Photo by Paul Tsui/National Geographic Travel Photographer of the Year Contest)

Miss Lovely Legs competition at the Pick 'n Pay hypermarket in Boksburg, South Africa, 1980. (Photo by David Goldblatt/Museum of Contemporary Art Australia)

Boxers Deontay Wilder, left, and Tyson Fury exchange words as they face each other at a news conference in Los Angeles, Wednesday, November 28, 2018. The pair are slated to fight Saturday night for Wilder's WBC heavyweight title. (Photo by Andrew Couldridge/Action Images via Reuters)

Villagers play traditional games as they take part in a Chyrachka rite during the Shrovetide celebration in the village of Tonezh, some 280 km of Minsk, on March 10, 2019. Chyrachka is a kind of birds that live in this area. (Photo by Sergei Gapon/AFP Photo)

A day-old lamb exploring new surroundings on the vernal equinox, considered the first day of spring, on March 20, 2019 at Coombes Farm in Lancing, England. (Photo by Andrew Hasson/Getty Images)

The cruise ship Viking Sky as it drifts after sending a Mayday signal because of engine failure in windy conditions near Hustadvika, off the west coast of Norway, Saturday March 23, 2019. The Viking Sky is forced to evacuate its estimated 1,300 passengers. (Photo by Odd Roar Lange/NTB Scanpix via AP Photo)

Spectators in fancy dress during Day 7 of The Championships – Wimbledon 2019 at the All England Lawn Tennis and Croquet Club on July 8, 2019 in London, England. (Photo by Carl Recine/Reuters)