A simulated casualty is evacuated during an emergency services exercise at the disused Aldwych underground station on February 22, 2012 in London, England. Operation Forward Defensive aims to test the response to a terrorist incident on the London Underground network during the 2012 Olympic Games. (Photo by Peter Macdiarmid/Getty Images)

Dancers perform during the Opening Ceremony of the Rio 2016 Olympic Games at Maracana Stadium on August 5, 2016 in Rio de Janeiro, Brazil. (Photo by Jamie Squire/Getty Images)

Two Teddy Bears from the 1920's sit on display in the museum section of the Merrythought Teddy Bear shop on April 5, 2011 in Ironbridge, England. Established in 1930, Merrythought has been hand-making Teddy Bears for over 80 years in Shropshire. The family-run company is the last remaining British teddy bear factory and is launching its latest limited edition bear to mark the royal wedding. The Commemorative Royal Wedding bear is limited to 75 and comes after its popular Prince William and Catherine Middleton bears completely sold out. Merrythought has also been selected by the London Olympic Games organisers to produce the official teddy bears of the London 2012 Olympic and Paralympic games. (Photo by Christopher Furlong/Getty Images)

In this handout image supplied by the Olympic Delivery Authority, workers carryout the installation of artist Monica Bonvicini's “RUN” sculpture in the plaza of the London 2012 Handball Arena at the Olympic Park on January 12, 2012 in London, England. (Photo by Olympic Delivery Authority via Getty Images)

2016 Rio Olympics, Opening ceremony, Maracana, Rio de Janeiro, Brazil on August 5, 2016. Athletes of Colombia take part in the opening ceremony. (Photo by Kai Pfaffenbach/Reuters)

Artist Richard Neave admires the sculpture “Sprinting” that he created with Denise Smith on March 12, 2012 in London, England. The model shows the body of elite athlete, Richard Whitehead, and forms the centre piece at the Anatomy Of An Athlete Exhibition opening at the Hunterian Museum. (Photo by Bethany Clarke/Getty Images)

Syrian refugee and Olympic swimmer Yusra Mardini is pictured during a training session in a pool at the Olympic park in Berlin, Germany on April 26, 2018. (Photo by Fabrizio Bensch/Reuters)

A man impersonating Kim Jong-un gestures during the athletics at the Rio 2016 Olympic Games at the Olympic Stadium in Rio de Janeiro on August 18, 2016. (Photo by Johannes Eisele/AFP Photo)