A Kenya Wildlife Services (KWS) veterinarian and security personnel back away from a tranquilised black-Rhino calf August 30, 2017 after she appeared to prematurely overcome the sedative at the Nairobi National Park, during an identification-tagging excercise to ease quick identification of resident rhino during anti-poaching patrols. (Photo by Tony Karumba/AFP Photo)

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)

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)

Revelers participate in J'Ouvert, an overnight celebration the night before the West Indies Day Parade in Brooklyn, NY on September 3, 2018. Violence in past years led NYPD to shut down the parade route until 2am. (Photo by Stephen Yang)

A person waits for donations at the exit from the Fred Meyer parking lot on South 19th street in Tacoma, Friday, February 8, 2019. (Photo by Peter Haley/The News Tribune via AP Photo)

Poppy, a female Crowned sifaka, inspects a photographer's camera in the enclosure at the zoo of Mulhouse, eastern France, on March 5, 2019. The Crowned sifaka is a critically endangered species from Madagascar. (Photo by Sebastien Bozon/AFP Photo)

A Palestinian woman reacts after inhaling tear gas fired by Israeli forces during a protest marking Land Day and the first anniversary of a surge of border protests, at the Israel-Gaza border fence, in the southern Gaza Strip on March 30, 2019. (Photo by Ashraf Abu Amrah/Reuters)

Fans and community members gather around a LAPD car along the procession route for Nipsey Hussle after his memorial at the Staples Center in Los Angeles, California, April 11, 2019. 4 people shot and 1 dead during the procession LAPD reported on late April 11, 2019 The Grammy-nominated artist was killed in front of The Marathon Clothing store he founded in 2017. (Photo by Kyle Grillot/AFP Photo)