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 masked participant carries a burning matress during the ancient carnival of Zubieta, in the northern Spanish Navarra province on January 30, 2018. The yearly three day festivities, revolving mainly around agriculture and principally sheep hearding, run on the last Sunday, Monday and Tuesday of January where Navarra Valley locals from two villages dress up and participate in a variety of activites as they perform a pilgrimage through each village. (Photo by Ander Gillenea/AFP Photo)

Storks that were saved by Bulgarian farmer Safet Ismail are pictured in the village of Zaritsa, Bulgaria, March 21, 2018. Dozens of people from villages in north-eastern Bulgaria took storks to their houses as a lot of the birds got injured due to freezing temperatures and snowfalls in the area over the last few days. (Photo by Stoyan Nenov/Reuters)

A Colombia fan clearly regrets invading the pitch as she is chased by a large security guard during the International Friendly match between Australia and Colombia at Craven Cottage on March 27, 2018 in London, England. (Photo by Charlotte Wilson/Offside/Getty Images)

A British Army Rolls Royce armoured car outside the Royal Ulster Constabulary police station on York Street in Belfast following riots after an Orange Order parade. (Photo by Fox Photos/Getty Images). 20th June 1935

Filipino boys play basketball at an improvised court hooked on multi-layered tombs at a public cemetery in Navotas, north of Manila, Philippines on Thursday Oct. 31, 2013. Filipinos are expected to flock to cemeteries on November 1 to remember their dead as they observe All Saints Day in this predominantly Roman Catholic country. (Photo by Aaron Favila/AP Photo)

A Swiss police officer accompanies a migrant from Syria carrying her baby, upon her arrival at the railway station in the north-eastern Swiss town of Buchs September 1, 2015. (Photo by Arnd Wiegmann/Reuters)

A tearful Beatle lover pleads unsuccessfully with a policeman to carry her fan button to Ringo, one of the four mop-top singers who drew squeals and shrieks from more than 30,000 spectators at two Indiana State Fair shows in Indianapolis on September 4, 1964. (Photo by Bob Daugherty/AP Photo)