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)

A wolf looks into the camera at the 30 km (19 miles) exclusion zone around the Chernobyl nuclear reactor in the abandoned village of Orevichi, Belarus, March 2, 2016. What happens to the environment when humans disappear? Thirty years after the Chernobyl nuclear disaster, booming populations of wolf, elk and other wildlife in the vast contaminated zone in Belarus and Ukraine provide a clue. (Photo by Vasily Fedosenko/Reuters)

Jordanian soldiers pose after the opening ceremony of eighth annual Warrior Competition at the King Abdullah Special Operations Training Center (KASOTC) in Amman, Jordan, May 2, 2016. Twenty Seven Teams from Eleven countries are participating in a competition to test their military skills. (Photo by Muhammad Hamed/Reuters)

On Saturday, September 2, 2017, local Chinese villagers gathered to celebrate a folk festival parade known as “Dog carrying Day” in Jiaobang village, Gedong Town, Jianhe county, Qiandongnan Miao and Dong Autonomous Prefecture, southwest China's Guizhou province. (Photo by Imaginechina/Rex Features/Shutterstock)

A man dressed as a traditional character in the “Baile de Negras” dance poses for a picture on the feast day of the Virgin of the Candelaria (Candlemas) in the town of Diriomo, some 45 km from Managua, Nicaragua on February 2, 2017 Candlemas falls forty days after Christmas and is celebrated by Catholics as the presentation of Christ at the Temple. (Photo by Inti Ocon/AFP Photo)

Members of the Knights Guard clean the ice during the Vegas Golden Knights' game against the Anaheim Ducks at T-Mobile Arena on January 14, 2021 in Las Vegas, Nevada. The Golden Knights defeated the Ducks 5-2. (Photo by Ethan Miller/Getty images/Profimedia)

Elizabeth Svensson (right), 35 and Klaudia Zakrzewska, 27, from London, arrive back in the UK at Heathrow Terminal 2, after being on holiday in Dubai for 15 days, during England's third national lockdown to curb the spread of coronavirus on Friday January 29, 2021. (Photo by Yui Mok/PA Images via Getty Images)

A Palestinian boy drinks water from a bucket near the site of his family's tented home, which according to Palestinians was dismantled by Israeli forces in Jordan Valley in the Israeli-occupied West Bank on February 2, 2021. (Photo by Raneen Sawafta/Reuters)