Collided passenger train cars are seen in Taebaek, South Korea, Tuesday, July 22, 2014. Two passenger trains collided head-on in eastern South Korea on Tuesday afternoon, killing one passenger and injuring dozens, fire officials said. (Photo by AFP Photo/Yonhap)

A giant river otter, the world's largest otter species, looks out of its enclosure at the newly completed River Safari in Singapore, on March 25, 2013. (Photo by Wong Maye-E/Associated Press)

US President Donald Trump' s daughter and senior White House adviser Ivanka Trump (2nd R) poses for a photo on a balcony of the VIP tent at the Olympic sliding centre with US army luge athletes Taylor Morris (L) and Matt Mortensen (2nd L), and US women’s bobsleigh silver medallist Lauren Gibbs (R) before the ski jump tower at the men' s four- man bobsleigh event of the Pyeongchang Winter Olympic games in Pyeongchang on February 25, 2018. (Photo by Eric Gaillard/Reuters)

An upside-down pair of pants is seen atop a mound of snow, Wednesday, February 20, 2019, the result of yet another snow storm to hit Omaha, Neb. The latest winter storm dumped more snow on top of the existing snow, creating a problem of what to do with all the cleared snow. (Photo by Nati Harnik/AP Photo)

The ruins of a castle stand above the town of Rocca Calascio, close to Santo Stefano di Sessanio in the province of L'Aquila in Abruzzo, inside the national park of the Gran Sasso e Monti della Laga, Italy, September 7, 2016. (Photo by Siegfried Modola/Reuters)

Wide-angle category winner. Part of the Illusion by Marcus Blatchford (UK). Location: National Dive & Activity Centre, Chepstow, Wales. “This is the deepest inland dive centre in the UK. The dive plan was to explore the deep end, but this time I dived ‘unplugged’ (without my strobes). With the exception of this change to my camera technique, there were no planned shots I wanted to achieve – just a fun dive with ad-hoc photos along the way. Shortly after this photo was captured, in 6C water and two hours of decompression ahead of us, we turned and started the long ascent back to the surface”. (Photo by Marcus Blatchford/Underwater Photographer of the Year 2016)

Four-year-old Rashida from Kobani, Syria, part of a new group of more than a thousand immigrants, sleeps as they wait at border line of Macedonia and Greece to enter into Macedonia near Gevgelija railway station August 20, 2015. (Photo by Ognen Teofilovski/Reuters)

Passengers wait at the departure hall of the Beijing Railway Station in central Beijing, China January 27, 2017 as China gears up for Lunar New Year, when hundreds of millions of people head home. (Photo by Damir Sagolj/Reuters)