West German police arrest a young man, one of the angry crowd throwing stones at a bus full of Soviet guards making their way to the Soviet War Memorial, 20th August 1962. The crowd were incensed by the death of 18-year-old Peter Fechter, who was shot while trying to cross the Berlin Wall a few days earlier. (Photo by Central Press/Hulton Archive/Getty Images)

A man (2nd L) takes pictures as visitors run away from a wave caused by a tidal bore which surged past a barrier on the banks of Qiantang River, in Hangzhou, Zhejiang province August 14, 2014. (Photo by Reuters/Stringer)

A Tenggerese shaman praying for worshippers at Widodaren cave during the Tenggerese Hindu Yadnya Kasada festival on July 31, 2015 in Probolinggo, East Java, Indonesia. The festival is the main festival of the Tenggerese people and lasts about a month. On the fourteenth day, the Tenggerese make the journey to Mount Bromo to make offerings of rice, fruits, vegetables, flowers and livestock to the mountain gods by throwing them into the volcano's caldera. The origin of the festival lies in the 15th century when a princess named Roro Anteng started the principality of Tengger with her husband Joko Seger, and the childless couple asked the mountain Gods for help in bearing children. The legend says the Gods granted them 24 children but on the provision that the 25th must be tossed into the volcano in sacrifice. The 25th child, Kesuma, was finally sacrificed in this way after initial refusal, and the tradition of throwing sacrifices into the caldera to appease the mountain Gods continues today. (Photo by Ulet Ifansasti/Getty Images)

A tourist stands in front of Italy's Mount Etna as it spews lava during an eruption on the southern island of Sicily, Italy on March 1, 2017. (Photo by Antonio Parrinello/Reuters)

Mount Etna, Europe's most active volcano, is seen from the side of a road as it spews lava during an eruption in the early hours of Thursday, March 16, 2017. Sicily's Mount Etna volcano unleashed an explosion Thursday, hurling molten rocks and steam that rained down on tourists, journalists and a scientist who scrambled to escape the barrage. Ten people were reported injured. (Photo by Salvatore Allegra/AP Photo)

A women rides a motor bike on a street covered with volcanic ash from an eruption of Mount Kelud, in Solo, Indonesia, Friday, February 14, 2014. A major volcanic eruption in Indonesia blasted clouds of ash and debris 18 kilometers (12 miles) into the air on Friday, forcing authorities to close six airports, cancel flights elsewhere in Southeast Asia and evacuate more than 100,000 people from the mountain. (Photo by Hafidz Novalsyah/AP Photo)

A villager watches as Mount Sinabung volcano erupts, in Kuta Tengah village, Karo Regency in Indonesia's North Sumatra April 1, 2015. The Indonesian volcano was dormant for 400 years before erupting in 2010. (Photo by Y. T. Haryono/Reuters)