Law enforcement officers stand, with some turning their backs, as New York City Mayor Bill de Blasio speaks on a monitor outside the funeral for NYPD officer Wenjian Liu in the Brooklyn borough of New York January 4, 2015. Tens of thousands of law enforcement officers from across the country gathered on Sunday for the funeral of the second of two New York City policemen killed last month in an ambush that galvanized critics of Mayor de Blasio. (Photo by Shannon Stapleton/Reuters)

A dragster supercharger hits cameraman Joe Rooks of Bowling Green, Ohio, in the back at the U.S. Nationals N.H.R.A. drag races in Indianapolis, Indiana, on Saturday, September 1, 1979. Rooks was knocked flat by the heavy blower from a dragster that turned over and disintegrated near Rooks. Rooks died en route to the hospital. (Photo by Chuck Robinson/AP Photo)

Students from Glasgow Art School modelling casual clothing and Buchan tartan in the annual Fashion Show for charities. During Rag Week students parade in the city streets wearing costumes designed and made by themselves. (Photo by Haywood Magee/Picture Post/Getty Images). 7th February 1953

A derelict farm house adorns the horizon as it sits in a field in the Lancashire Countryside on January 26, 2012 in Burscough, England. (Photo by Christopher Furlong/Getty Images)

Pictures of deceased people are seen inside a chapel at a cemetery in the village of Smoljinac, Serbia, October 25, 2016. From a distance, the cemetery in the eastern Serbian village of Smoljinac looks like a residential neighbourhood eerily placed among graves. But once inside the grounds, after passing a section with the usual stone slabs, visitors find rows of small bungalows painted in pastel colours. They have one or two rooms, large windows and ornate plaques – some inside, some outside – memorialising the deceased. These are the burial chapels of Smoljinac, cosy cabins with a furnished room inside, a storage place for wreaths and funeral paraphernalia, and the family crypt below. Some even have electric power inside. (Photo by Marko Djurica/Reuters)

A saltwater crocodile with a tyre around its neck is seen in Palu river in Palu on January 16, 2018. Indonesian conservation officials are racing against time to locate and rescue a saltwater crocodile that has had a tire wrapped around its for more than a year on the island of Sulawesi. (Photo by AFP Photo/ARFA)

A man takes a photograph of his friend as thick smoke rises from a fire, which broke out at oil wells set ablaze by Islamic State militants before they fled the oil-producing region of Qayyara, Iraq, January 28, 2017. (Photo by Muhammad Hamed/Reuters)

Pedestrians cover their face as they walk along the dusty road in Kathmandu, Nepal February 27, 2017. Nepal has forced 2,500 old vehicles off roads in its capital city of Kathmandu, part of a fight against alarming air pollution levels that have hit nine times World Health Organisation (WHO) limits. Air pollution has been a chronic problem in rapidly growing Kathmandu, which sits in a Himalayan valley and is home to more than 3mn people. (Photo by Navesh Chitrakar/Reuters)