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)

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)

Kelsey Smith of New Zealand gets her stick caught on the shorts of Hollie Pearne-Webb of England during Women's Semi Final Hockey match between England and New Zealand on day eight of the Gold Coast 2018 Commonwealth Games at Gold Coast Hockey Centre on April 12, 2018 on the Gold Coast, Australia. (Photo by Matt King/Getty Images)

Naked riders seen participating during the World Naked Bike Ride to demonstrate the vulnerability of cyclists on city streets in London, United Kingdom on June 9, 2018. People chose to ride naked to celebrate cycling and body freedom. (Photo by Brais G. Rouco/SOPA Images/LightRocket via Getty Images)

Model friends Bella Hadid, Kendall Jenner, Stella Maxwell and actress Kristen Stewart and are seen having dinner together in Milan, Italy on June 16, 2018. Bella and Kendall cheekily showed the camera middle finger while couple Stella and Kristen talked. (Photo by Splash News and Pictures)

A participant with a face painted as popular Mexican figure “Catrina” attends the Day of the Dead event at a National house for Mexican fans in central Moscow, a host city for the 2018 FIFA World Cup, Russia June 29, 2018. (Photo by Sergei Karpukhin/Reuters)

Ministry of Defence handout photo of Chinooks from RAF Odiham as they take part in the Royal Air Force flypast over central London to mark the centenary of the RAF on Tuesday, July 10, 2018. (Photo by SAC Pippa Fowles (RAF)/PA Wire)

Singer Ariana Grande performs during the funeral service for Aretha Franklin at Greater Grace Temple, Friday, August 31, 2018, in Detroit. Franklin died August 16, 2018 of pancreatic cancer at the age of 76. (Photo by Mike Segar/Reuters)