An aerial view shows a sinkhole 3.5 km (2 miles) to the east of Solikamsk-2 mine in Perm region, November 20, 2014. Shares in Russia's Uralkali, the world's top potash producer, fell sharply for a second day on Wednesday after a mine accident that could reduce global supplies and push up prices of the crop nutrient worldwide. Uralkali shares have fallen 28 percent since Tuesday when it suspended work at its Solikamsk-2 mine, which accounts for a fifth of the company's output and 3.5 percent of global capacity, following an inflow of water. A sinkhole, stretching 30 by 40 metres (yards), found at an abandoned mine 3.5 km (2 miles) to the east, increased concern about the future of the mine because an inflow of water and the resulting sinkhole in 2006 forced another Uralkali operation to shut permanently. (Photo by Reuters/Press service of Uralkali company)

Laura Paipo (L), first blind principal in Uruguay participates in a street race with her sighted guide and friend Amparo Bauter in Montevideo, October 4, 2015. Paipo, 55, who took office on August 10, 2015 became the first blind principal of a special school which specializes in the education of visually impaired students. (Photo by Andres Stapff/Reuters)

Star Wars collector James Burns, 44, poses for a photograph with some of his collection in London December 2, 2015. He said “I've met so many wonderful people, all over the world. It's a wonderful community of likeminded people with an interest in Star Wars. There's nothing else like it”. (Photo by Paul Hackett/Reuters)

A man takes photo of his colleague with a mobile phone on the burning oil tanker at the ship-breaking yard in Gaddani, Pakistan, November 2, 2016. Reports state that at least eighteen workers were killed and more than 100 were wounded in a blast at Gaddani ship breaking yard near Karachi on 01 November. Initial reports suggest the blast occurred when a gas cylinder exploded inside an oil tanker being broken up for scrap. (Photo by Akhtar Soomro/Reuters)

A Los Angeles County firefighter puts water a burning house in a wildfire in the Lake View Terrace area of Los Angeles Tuesday, December 5, 2017. Ferocious winds in Southern California have whipped up explosive wildfires, burning a psychiatric hospital and scores of other structures. Tens of thousands of people have been ordered evacuated. (Photo by Chris Carlson/AP Photo)

An Afghan policeman stands guard in front of a French restaurant “Le Jardin” after a suicide attack in Kabul, Afghanistan January 2, 2016. A suicide attack on a French restaurant in the Afghan capital Kabul on Friday killed a 12-year-old boy and wounded more than a dozen other people, officials said. (Photo by Mohammad Ismail/Reuters)

People at a Czech Stop look at a cloud of smoke rising from the explosion in West, Texas, April 17, 2013. (Photo by Andy Bartee via Dallas Morning News/MCT)

Sunday night, Lauren Watts searches for her dog in Mayflower, Arkansas., after a tornado struck the town. (Photo by Benjamin Krain/The Arkansas Democrat-Gazette)