Blankets cover the bodies of a woman (right) and a man (left background) hit by a northbound Penn Central train (background) as they waited with a crowd at Pennsylvania Railroad station in Elizabeth, N.J. on June 8, 1968 to view the southbound train carrying the body of Sen. Robert F. Kennedy to Washington. The woman was identified as Mrs. Antoinette Severini, 54, and the man, John Curia (age unavailable), both of Elizabeth. (Photo by AP Photo)

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)

Kate Upton, from left, Maya Jama and Victoria Justice attend the Philipp Plein 2018 Fall/Winter Runway Show during New York Fashion Week at the Brooklyn Navy Yard on Saturday, February 10, 2018, in New York. (Photo by Brent N. Clarke/Invision/AP Photo)

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)

Yogis, Israeli and foreigners, participate in the Arava Yoga Annual festival at the ancient copper mines area of the Timna Valley, in the southern Arava region of Israel, north of Eilat on November 2, 2018. (Photo by Menahem Kahana/AFP Photo)

This aerial picture taken on the night of November 12, 2018 shows traffic on an elevated intersection in downtown Shanghai, China. (Photo by Johannes Eisele/AFP Photo)

Undated handout photo issued by Take a View of the winner of the Adobe Prize of the Landscape Photographer of the Year Awards, The Daymark, Brixham, Devon, England by Will Milner (lives Oxfordshire). Issue date: Monday October 15, 2018. (Photo by Will Milner/PA Wire Press Association)