Paramedics carry an injured woman out from a subway station after a rush-hour subway train derailment, to be transported by a medical helicopter in Moscow, Russia, on Tuesday, July 15, 2014. A rush-hour subway train derailed in Moscow Tuesday, killing 20 people and injuring at least 150, emergency officials said. Several cars left the track in the tunnel after a power surge triggered an alarm, which caused the train to stop abruptly. (Photo by Ivan Sekretarev/AP Photo)

A couple passes the sculpture “Transformer” by Chinese artist Bi Heng during snowfall in Kassel, central Germany, Tuesday March 12, 2013. Frankfurt airport closed, a quarter of flights out of Paris were canceled, Belgium suffered record traffic jams and high-speed trains were stuck in stations – all because of a sudden dump of oddly late snowfall on Western Europe. Less prepared for the kind of heavy snow that regularly hits northern and eastern neighbors, France, Britain and Belgium struggled Tuesday to keep moving amid the frosty, blustery conditions. (Photo by Uwe Zucchi/AP Photo/Dpa)

In this photo taken Sunday, May 6, 2012, Denis Lutskevich, left, is detained by police during an opposition rally in Bolotnaya Square in Moscow. The former naval cadet and first-year student, 21-year-old Lutskevich was attending his first protest when he was detained, and is still in prison Monday May 6, 2013, on the first year anniversary of the protest. (Photo by Pavel Golovkin/AP Photo)

In this July 24, 2016 photo, a pilgrim takes a bath in a sacred mud pool during the annual Voodoo celebration in Plaine-du-Nord, Haiti, Saturday, July 23, 2016. Pilgrims come to bathe in the mud and make offerings expecting a miracle. (Photo by Dieu Nalio Chery/AP Photo)

A woman waits at a polio immunisation health centre, in Maiduguri, Borno State, Nigeria, August 29, 2016. Nigeria's military has liberated large swathes of land from Boko Haram but a ride with an army convoy, all guns firing for fear of ambush, shows how far the northeast is from normality after a brutal Islamist insurgency that has displaced millions. (Photo by Afolabi Sotunde/Reuters)

In this Feb. 17, 2017 photo, surfers walk to La Pampilla beach in Lima, Peru. Night surfing apparently came about in Lima because of a dispute with the capital municipality that in 2015 increased the width of a road that runs along the coast. The surfers protested the construction for months by camping on the asphalted beach area, but in the end the municipality prevailed, with support from the police. At the end of 2016, perhaps to win over the surfers, Lima's mayor set up beach lights that allows for night surfing. (Photo by Rodrigo Abd/AP Photo)

A boy dressed as Hindu Lord Shiva poses before performing in a religious procession at the Mahashivratri festival in Allahabad, India, March 7, 2016. Hindus across the country celebrate Mahashivratri, better known as Lord Shiva's wedding anniversary. (Photo by Jitendra Prakash/Reuters)