School teachers and staff members take part during an active shooter training at James I. O'Neill High School in Highland Falls, New York, U.S., December 12, 2017. (Photo by Eduardo Munoz/Reuters)

Five-month-old baby elephant Fah Jam swims during a hydrotherapy treatment as part of a lengthy rehabilitation process to heal her injured front left foot at a rehabilitation center in Pattaya, Thailand January 5, 2017. The baby elephant was injured at three months old when she got stuck in an animal snare put up by villagers to prevent elephant intrusions in Chanthaburi province. (Photo by Athit Perawongmetha/Reuters)

A person enter in sauna on the peak of Mount Lagazuoi in Cortina D'Ampezzo, Italy January 16, 2018. Picture taken January 16, 2017. (Photo by Stefano Rellandini/Reuters)

Catherine Hollis of Chester, Pa., and Izzy Weintraub of Atlantic City eat Cherrystone clams at Atlantic City's annual clam-eating contest September 16, 1946. They finished 96 and 66 clams respectively in 20 minutes. (Photo by Sam Myers/AP Photo)

An Army Sikorsky R-5 helicopter, undergoing record trials, demonstrates its lifting power by carrying 17 persons and pilot aloft as female onlookers wave in Bridgeport, Conn., January 10, 1946. During the tests records were claimed for altitude speed and both altitude and speed with payload. (Photo by Anthony Camerano/AP Photo)

A Hong Kong Correctional Services Dog Unit (CSDU) officer demonstrates training at the CSDU training facility in Stanley, Hong Kong, China, 27 February 2018. The Hong Kong CSDU consists of 29 staff members divided across six dog teams. According to the department's latest figure from 2017, the average daily penal population of Hong Kong was 8,529. (Photo by Jérôme Favre/EPA/EFE)

Trainer Lawney Hill poses for a photograph as she wears tights over her face to keep out the cold after taking her horses out on the all-weather gallops in Tetsworth, Britain, March 2, 2018. (Photo by Eddie Keogh/Reuters)

Comedian Chevy Chase gets a kiss on his ear from co-star Benji as the two held a press conference in Los Angeles, September 6, 1979, at which they announced their up-coming movie “Oh Heavenly Dog” would begin filming this month. The film will be shot on location in London, Berlin and Paris; but due to British quarantine laws a double will be used for Benji at the London location. (Photo by Nick Ut/AP Photo)