A police officer stands at a police cordon near the scene of a terror attack in London, U.K., on Sunday, June 4, 2017. A van swerved into Saturday-night crowds on London Bridge, before three men got out and went on a stabbing rampage through nearby bars. (Photo by Luke MacGregor/Bloomberg)

Cottbus Aviation Museum specialists prepare a Soviet Tupolev 134 A passenger plane for dismantlement in Gruenz, Germany, 10 July 2017. The team is preparing the 29 ton plane for transport from a garden in Gruenz to the Aviation Museum in Cottbus. The plane' s owner acquired it in 1991 and transported it with nine tractors and numerous helpers to his vegetable garden where he planned to open a cafe. The plane, formerly used by the East German Stasi for anti- terror operations training, is 30 metres long. (Photo by Jens Büttner/Zentralbild/DPA)

A woman, wearing a traditional Sevillana dress, performs as she asks for alms in downtown Malaga, Spain, April 28, 2016. (Photo by Jon Nazca/Reuters)

Eight-year-old Lactatia a.k.a. Nemis Quinn Mélançon Golden gets a makeover by Ginger Minj during RuPaul's DragCon NYC 2017 at The Jacob K. Javits Convention Center on September 9, 2017 in New York City. (Photo by Santiago Felipe/Getty Images)

A Boeing 777-300 from Swiss International Airlines lands on a foggy morning at Zurich Airport, on Friday, October 13, 2017, in Zurich, Switzerland. The high humidity renders the air vortex visible. (Photo by Christian Merz/Keystone via AP Photo)

Behaviour: Mammals category. Giant Gathering by Tony Wu, USA. Dozens of sperm whales mingled noisily off Sri Lanka’s northeast coast, stacked as far down as Tony could see. This was a congregation of dozens of social units, like a gathering of the clans. Aggregations like this could be a critical part of the whales’ rich social lives but are rarely reported. Some two thirds of the population was wiped out before commercial whaling was banned in 1986. This kind of major gathering could be “a sign that populations are recovering”, says Tony. (Photo by Tony Wu/Wildlife Photographer of the Year 2017)

A woman is helped out of the wrecked car of a train that derailed at the station of Pioltello Limito, on the outskirts of Milan, Italy, Thursday, January 25, 2018. Italian officials said that the commuter train derailed in northern Italy, killing some people, seriously injuring 10 and trapping others heading into Milan at the start of the work day. (Photo by AP Photo/Stringer)

Migrants with a stick, stones and knife fight with each other after a brawl erupted over a place in an overcrowded train heading to the Serbian border at the train station in Gevgelija, The Former Yugoslav Republic of Macedonia, 14 August 2015. (Photo by Georgi Licovski/EPA/EFE)