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)

A member of Kyrgyzstan's first female hockey team arrives for a training session in the village of Otradnoye, Kyrgyzstan on February 4, 2020. Based in the remote village of Otradnoe, 249 miles (400 kilometres) east of the country's capital Bishkek, the team comprises of around 15 girls from a local school and uses a flooded allotment to train on during the winter months. (Photo by Vladimir Pirogov/Reuters)

Migrants climb through the windows of a train bound for Serbia at the train station in Gevgelija, The Former Yugoslav Republic of Macedonia, 19 July 2015. Thousands of migrants who crossed Greece are on their way through Macedonia towards Serbia in order to access other European countries. Hungary in mid-July started to put up a fence on its border with Serbia, which makes the situation with the migrants in the transit countries even more complicated. The European countries on 20 July will discuss the quota of how many migrants each country should accept. (Photo by Georgi Licovski/EPA)

Students carry a female trainee who has fallen into a stupor during high intensity training at Tianjiao Special Guard/Security Consultant camp on the outskirts of Beijing December 1, 2013. Former Chinese soldier Chen Yongqing has big ambitions for his bodyguard training school Tianjiao, which he says is China's first professional academy to train former soldiers and others as personal security guards. Chen charges 500,000 yuan ($82,400) a year for each protector as China's rich and famous look to bolster their safety and sense of importance. (Photo by Jason Lee/Reuters)

Team Strong Silvers member Ngai Hin Kwok, 66, works out as teammate Ng Siu Chi, 57, watches at a stadium in Singapore March 15, 2015. Team Strong Silvers, is a group of senior citizens who train in calisthenics. The trio trains individually at least three times a week, and meets up for joint calisthenics at least twice a month. (Photo by Edgar Su/Reuters)

Trainees of the Tianjiao Special Guard/Security Consultant bodyguard training camp watch their instructor use a scarf to cover a student's head during a demonstration of close-quarter combat skills at a special course on flight safety inside a scale model of a passenger jet at a flight attendant training centre on the outskirts of Beijing, March 18, 2014. Inspired by the missing Malaysia Airlines Flight MH370, the company wanted to emphasize the importance of aviation safety by teaching their trainees emergency evacuation procedures and close-quarter combat skills to handle situations such as natural disasters and plane hijacks, according to the company. (Photo by Jason Lee/Reuters)

In this Monday, July 25, 2016 photo, skydiver Luke Aikins smiles as he jumps from a helicopter during his training in Simi Valley, Calif. After months of training, this elite skydiver says he's ready to leave his chute in the plane when he bails out 25,000 feet above Simi Valley on Saturday. That's right, no parachute, no wingsuit and no fellow skydiver with an extra one to hand him in mid-air. (Photo by Jae C. Hong/AP Photo)