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)

A chicken gingerly crosses the double yellow line of a country road near Roseburg in western Oregon, USA on July 16, 2018. (Photo by Robin Loznak/ZUMA Wire/Alamy Live News)

Ballerinas perform during an ice-cream factory promotional event at an observation floor of the Moscow International Business Centre, also known as “Moskva-City”, in Moscow, Russia October 25, 2018. (Photo by Shamil Zhumatov/Reuters)

A boy plays on the glass at Thailand's first skywalk in Bangkok, Thailand on November 18, 2018. (Photo by Soe Zeya Tun/Reuters)

In this Tuesday, March 12, 2019 photo, a visitor takes part in an immersive experience showing visitors how dogs see from inside the head of a dog at the California Science Center in Los Angeles. A new exhibit at a Los Angeles museum examines the relationship between dogs and humans and explores why the two species seem to think so much alike and get along so well. “Dogs! A Science Tail” opens Saturday, March 16, 2019, at the California Science Center. (Photo by Richard Vogel/AP Photo)

A protester is taken away by police during an electoral campaign closing rally of Spain's far-right party VOX in Madrid, Spain on April 26, 2019. (Photo by Juan Medina/Reuters)

Boys contort their faces as they participate in a game where they need to slide a coin from their forehead to their mouth to win, during the annual Feast Day of St. Rita of Cascia in Manila, Philippines on May 19, 2019. (Photo by Noel Celis/AFP Photo)

Members of the U.S. Army's Golden Knights parachute team perform during the Bethpage Air Show as part of a Memorial Day event at Jones Beach on Long Island, New York, U.S., May 25, 2019. (Photo by Johnny Milano/Reuters)