An African immigrant tries to jump a fence into a ferry terminal in the western Greek town of Patras April 28, 2015. Afghan, Iranian and Sudanese immigrants, living precariously in abandoned factories in Patras, southwest Greece, try to stow away on nearby ferries to Italy as they seek a better life in Europe beyond crisis-hit Greece. (Photo by Yannis Behrakis/Reuters)

Framed by the setting sun, an American Bison grazes at the Tallgrass Prairie National Preserve on Tuesday, April 28, 2015, near Strong City, Kan. The buffalo herd at Tallgrass is one of the few herds of wild bison left in the United States. (Photo by Travis Heying/The Wichita Eagle via AP Photo)

Venezuela: An anti-government protester wearing a Guy Fawkes mask throws a molotov cocktail at the Bolivarian National Police during clashes in Caracas, Venezuela, Thursday, April 17, 2014. Opposition protesters have been demonstrating against high crime, high inflation and shortages of basic goods since mid-February. (Photo by Ramon Espinosa/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)

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)

A “nail house”, the last building in the area, sits in the middle of a road under construction in Nanning, Guangxi Zhuang Autonomous Region April 10, 2015. According to local media, the owner of the house didn't reach an agreement with the local authority about compensation of the demolition. (Photo by Reuters/Stringer)

Central Bangkok and the Chao Phraya River are seen from an abandoned skyscraper in Bangkok April 19, 2015. The abandoned building, known as Satorn Unique, dubbed the “ghost tower” was destined to become one of Bangkok's most luxurious residential addresses but construction was never completed as the Thai economy was hit during the 1997 Asian Financial Crisis. Now, many travellers visit and explore 49-storey skyscraper. (Photo by Athit Perawongmetha/Reuters)