National Guardsmen are put through riot training in Boston's Commonwealth Armory on Friday, October 18, 1974. Massachusetts Gov. Francis W. Sargent called up the guard to quell school violence, but the city has been relatively calm and the guard has remained in the armories. (Photo by JWG/AP Photo)

Members of Imperio Serrano samba school get ready prior to their entrance during 2023 Carnival parades at Marquês de Sapucaí Sambodrome on February 19, 2023 in Rio de Janeiro, Brazil. (Photo by Buda Mendes/Getty Images)

Pixie Howitt,left, Jada-Jo Branney and Darcey McKechnie, pupils at the Dance School of Scotland, pose alongside works in the exhibition Discovering Degas: Collecting in the Time of Sir William Burrell, in Glasgow on September 3, 2024. (Photo by Wattie Cheung/The Times)

Frida, a rescue dog belonging to the Mexican Navy, with her handler Israel Arauz Salinas, takes a break while participating in the effort to look for people trapped at the Rebsamen school in Mexico City, on September 22, 2017, three days after the devastating earthquake that hit central Mexico. (Photo by Omar Torres/AFP Photo)

Freshmen in Zhengzhou Institute of Aeronautical Industry Management head bottles of mineral water for upright stand during military training on September 17, 2015 in Zhengzhou, Henan Province of China. More than 6,800 freshmen in the school are required to take part in the military training. (Photo by ChinaFotoPress/ChinaFotoPress via Getty Images)

A pupil of the Dao ethnic tribe returns home from school along a hillside path at Suoi Thau village in Hoang Su Phi district of Vietnam's northern province of Ha Giang, located at the border with China, September 18, 2015. (Photo by Reuters/Kham)

A Thai mahout and his elephant, both dressed as Santa Claus pass in font of a large photograph of Thai King Bhumibol Adulyadej following a Christmas event at a school in the world heritage city of Ayutthaya, north of Bangkok, Thailand, 24 December 2015. The annual event is held to celebrate the Christmas season in the overwhelmingly Buddhist kingdom. (Photo by Diego Azubel/EPA)

Joe Deedon, president of TAC ONE Consulting, demonstrates searching for a shooter in a middle school during an Active Shooter Response course offered by TAC ONE in Denver April 2, 2016. According to TAC ONE, the course, which is offered for the first time to concealed weapons permit carrying civilians, is designed at preparing people to effectively save lives prior to the arrival of law enforcement at an active shooter incident. (Photo by Rick Wilking/Reuters)