A police officer stands at a police cordon near the scene of a terror attack in London, U.K., on Sunday, June 4, 2017. A van swerved into Saturday-night crowds on London Bridge, before three men got out and went on a stabbing rampage through nearby bars. (Photo by Luke MacGregor/Bloomberg)

Medic James E. Callahan of Pittsfield, Mass., gives mouth-to-mouth resuscitation to a dying soldier in war zone D, about 50 miles northeast of Saigon, June 17, 1967. Thirty-one men of the 1st Infantry Division were reported killed in the guerrilla ambush, with more than 100 wounded. (Photo by Henri Huet/AP Photo)

Wales' Gemma Frizelle competes in the Team Final and Individual Qualification Sub Division 2 at the Coomera Indoor Sports Centre during day seven of the 2018 Commonwealth Games in the Gold Coast, Australia on April 11, 2018. (Photo by David Gray/Reuters)

Guests attend preview event for “Candytopia”, the outrageously interactive candy wonderland, opening in San Francisco, USA on September 6, 2018. (Photo by Kelly Sullivan/Getty Images for Candytopia)

An air raid drill at Seattle College caught students William Bates, left, and Edna Mae Farrell, right, while they were eating their lunch in the school café, but they simply took shelter under the table and continued eating in Seattle, Washington, March 17, 1942. Air raid wardens said 350 students left their classrooms and assembled in shelters within one minute in first at the college. (Photo by AP Photo)

Bollywood actress and former p*rn star Sunny Leone stands with her wax likeness during its unveiling at the Madame Tussauds museum in New Delhi, India, Tuesday, September 18, 2018. The statue unveiled Tuesday represents the 37-year-old celebrity's acceptance by mainstream Indian society even as conservative Indian politicians condemn her p*rn-star past. (Photo by Anupam Nath/AP Photo)

In this January 27, 2019, photo, Hindu holy men of monastic order Juna Akhara participate in a ritual before becoming Naga Sadhus or naked holy men at Sangam, the confluence of three holy rivers during the Kumbh Mela or pitcher festival in Prayagraj Uttar Pradesh state, India. At every Kumbh, including this year's, thousands of devotees were initiated into the reclusive sect of the Naga Sadhus, naked, ash-smeared cannabis-smoking Hindu warriors and onetime-armed defenders of the faith who for centuries have lived as ascetics in jungles and caves. (Photo by Rajesh Kumar Singh/AP Photo)

Model Daisy-May Demetre, 9 year-old double amputee who will walk the runway during Paris Fashion Week, is seen during a photo shoot a day before the show of luxury children's wear label Lulu et Gigi in Paris, France, September, 26, 2019. (Photo by Gonzalo Fuentes/Reuters)