In this March 14, 2015 photo, tourists take pictures from a viewing area at Iguazu Falls in Brazil. From walkways and bridges, viewers can count 270 water falls almost 100 meters (330 feet) high. (Photo by Jorge Saenz/AP Photo)

A gallery staff member walks past Fleeting Monument (1985) by artist Cornelia Parker, one of the works on display at Yorkshire Sculpture Parks Longside Gallery as part of the “Making It: Sculpture in Britain 1977-1986” exhibition on March 27, 2015 in Barnsley, England. (Photo by Christopher Furlong/Getty Images)

A photographer takes picture of an automotive model during the 36th Bangkok International Motor Show in Bangkok, Thailand, March 24, 2015. No automotive event is complete without the latest offering of high-end cars and motorcycles, and the obligatory accessories stationed at each booth: nubile, young auto-show girls in skimpy, skinsqueezing outfits. This year's Bangkok International Motor Show did not disappoint, attracting a larger horde of eager, flesh-seeking photographers than actual fans of automobiles. (Photo by Jurnasyanto Sukarno/JG 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)

A devotee takes a holy bath at the Balaju Baise Dhara (22 water spouts) during the Baishak Asnan festival in Kathmandu April 4, 2015. Devotees believe that the water from these stone spouts, which is collected from the catchment area of the Nagarjun forest behind the spouts, will cure pains and skin diseases. (Photo by Navesh Chitrakar/Reuters)

In this Wednesday, March 18, 2015 photo, limestone quarry workers walk through a cloud of dust spewed into the air by rotor blades of the stone-cutting machinery in the desert of Minya, southern Egypt. Around 45,000 people, including children, work in an estimated 1,500 quarries, digging out stones that later will be used in construction or powdered to be used by pharmaceutical and ceramic companies. (Photo by Mosa'ab Elshamy/AP Photo)

People carry cutouts of coffins during a march to commemorate the more than 617 people they say have been killed by law enforcement in LA County since 2000, in Los Angeles, California April 7, 2015. (Photo by Lucy Nicholson/Reuters)

Sikh devotees participate in the Baisakhi festival at Panja Sahib shrine in Hassan Abdel April 13, 2015. Hundreds of Indian Sikh pilgrims arrived into Pakistan to celebrate the Baisakhi festival with Pakistani Sikhs at the shrines of Panja Sahib and Nankana Sahib, the birth place of Sikh faith founder Guru Nanak Dev. (Photo by Caren Firouz/Reuters)