Ammunition airlift into besieged Khe Sanh, Operation Pegasus, April 1968. (Photo by Larry Burrows/AP Photo)

British tourist participates in a crab race at the annual Tobago Heritage Festival, at Buccoo Integrated Facility, in Tobago island, Trinidad and Tobago on July 29, 2018. (Photo by Andrea De Silva/EPA/EFE)

Supermodel Bella Hadid (L) arrives at the Peppermint Club to watch her bestfriend, Jesse Jo Stark, perform her music in Los Angeles, CA on August 29, 2018. (Photo by Photographer Group/Splash News and Pictures)

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)

Hollydell Poseidon ridden by Madeline Reader-Smith takes part in the Shetland Pony Grand National Flat Race in Aid of Bob Champion Cancer Trust during day two of the Cambridgeshire Meeting at Newmarket Racecourse on Friday, September 28, 2018. (Photo by Mike Egerton/PA Wire)

Central Palo Seco power station of the Puerto Rico Electric Power Authority (PREPA) is seen behind a cemetery, in San Juan, Puerto Rico on January 22, 2018. (Photo by Alvin Baez/Reuters)

A tamed hawk sits on a chair next to a participant during a traditional hunting contest in Almaty, Kazakhstan on December 1, 2018. (Photo by Pavel Mikheyev/Reuters)

The US' winner Mikaela Shiffrin celebrates during a flowers ceremony after the women's Super G event of the 2019 FIS Alpine Ski World Championships at the National Arena in Are, Sweden, on February 5, 2019. (Photo by Denis Balibouse/Reuters)