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)

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)

Civilians present their rations cards in order to receive humanitarian food aid being distributed by the Iraqi Red Crescent, in the eastern side of Mosul, Iraq, Tuesday, January 31, 2017. Iraqi forces declared Mosul's eastern half fully liberated, just over three months after the operation to retake the city from IS was formally launched in October. (Photo by Khalid Mohammed/AP Photo)

Maya, 8, and Kishore, 13, pose for a wedding photo inside their new home, the day after the Hindu holy day of Akshaya Tritiya, called Akha Teej in North India. Despite legislation forbidding child marriage in India (Child Marriage Restraint Act-1929) and the much more progressive Prohibition of Child Marriage Act (2006) and many initiatives to prevent child marriage, marrying children off at a very tender age continues to be accepted by large sections of society. (Photo by Stephanie Sinclair/VII Photo Agency)

Masked participants stand in St.Mark's Square during the Carnival on February 10, 2007 in Venice, Italy. (Photo by Marco Di Lauro). P.S. All pictures are presented in high resolution.

The Oshkosh M-ATV – MRAP (Mine Resistant Ambush Protected) vehicle developed by the Oshkosh Corporation of Oshkosh, Wisconsin. It is designed to provide the same levels of protection as the larger and heavier previous MRAPs but with improved mobility and it is intended to replace M1114 HMMWVs. (wikipedia) (Photo by Alex Wong/Getty Images)

In this March 22, 1975 file photo, a refugee clutches a baby as a government helicopter gunship carries them away near Tuy Hoa, Vietnam, 235 miles northeast of Saigon. They were among thousands fleeing from Communist advances. AP Photographer Nick Ut will be retiring from the AP in March 2017 after 51 years of taking photographs from the front lines of the Vietnam War to the red carpets of Hollywood. (Photo by Nick Ut/AP Photo)

A cadet from the Interior Ministry with the word Fidel painted on her face attends a rally honoring the late Cuban leader at the Revolution Plaza in Havana, Cuba, Tuesday, November 29, 2016. Schools and government offices were closed Tuesday for a second day of homage to Fidel Castro, with the day ending in a rally on the wide plaza where the Cuban leader delivered fiery speeches to mammoth crowds in the years after he seized power.Fidel Castro passed away Friday Nov. 25. He was 90. (Photo by Ramon Espinosa/AP Photo)