Swiss rescue workers wheel a wounded person on a stretcher after two regional trains crashed head on near Granges-Pres-Marnand near Payerne in western Switzerland July 29, 2013. The two trains collided in the Swiss canton of Vaud on Monday evening, injuring about 40 people, four seriously, Swiss news agency ATS reported. There was no immediate report of any deaths in the crash. (Photo by Denis Balibouse/Reuters)

Gers, traditional Mongolian tents, are seen on a hill in an area known as a ger district in Ulan Bator June 26, 2013. Approximately 60 percent of the population of Ulan Bator live in settlements known as ger districts and in many cases residents have limited access to basic services such as water and sanitation. According to a 2010 National Population Center census, every year between thirty and forty thousand people migrate from the countryside to the capital Ulan Bator. Ger districts in the city have been expanding rapidly in recent years. Mongolia is the world's least densely populated country, with 2.8 million people spread across an area around three times the size of France. (Photo by Carlos Barria/Reuters)

Parent hedgehogs Maria, left, and Gosha, 2nd right, eat with their albino babies in a private Zoo in Moscow, Russia, Thursday, August 22, 2013. Three rare albino hedgehog babies, born on the same day as Britain's new prince, have moved into a miniature castle at a Moscow petting zoo. The three are named after the Prince of Cambridge – George, Alexander and Louis. On Thursday, when they turned one month old, they were shown their new home at the All-Russia Exhibition Center. (Photo by Alexander Zemlianichenko Jr./AP Photo)

One month-old endangered Bornean Orang Utan sleeps on his mother named Miri on Wednesday, March 6, 2013, in Singapore. The Singapore Zoo is renowned for its flagship animal, the Orang Utan, and exhibits both the endangered Bornean and critically endangered Sumatran sub-species in a social setting. It is also known for its efforts in promoting and educating the public about the importance of wildlife conservation through its educational programs and breeding of these endangered species. (Photo by Wong Maye-E/AP Photo)

Base jumper Denis Odintsov from Russian leaps from the 300-meters Open Deck of the Malaysia's landmark Kuala Lumpur Tower during the International Tower Jump in Kuala Lumpur on September 27, 2013. Some 103 professional base jumpers from 20 countries are taking part in the annual event. (Photo by Mohd Rasfan/AFP Photo)

An Indian woman collects camel dung during the annual cattle fair in Pushkar, in the western Indian state of Rajasthan, Sunday, November 10, 2013. Pushkar, located on the banks of Pushkar Lake, is a popular Hindu pilgrimage spot that is also frequented by foreign tourists who come to the town for the annual cattle fair and camel races. (Photo by Ajit Solanki/AP Photo)

Villagers look on as Mount Sinabung volcano spews thick volcanic ash, as seen from Beganding village in Karo, North Sumatra province, on May 19, 2017. Sinabung roared back to life in 2010 for the first time in 400 years. After another period of inactivity, it erupted once more in 2013 and has remained highly active since. (Photo by Ivan Damanik/AFP Photo)