In this photo taken Tuesday, October 14, 2014, skulls and bones are stacked at the Catacombs in Paris, France. The subterranean tunnels, stretching 2 kilometers (1.24 miles), cradle the bones of some 6 million Parisians from centuries past and once gave refuge to smugglers. The site used to close at 5 p.m., but is now staying open until 8 p.m. The change is mainly aimed at allowing more people to visit and reducing long lines, since it can only hold a limited number of people at a time and visits can't be reserved in advance. (Photo by Francois Mori/AP Photo)

In this October 7, 2014, photo, Fredrick Brower, center, helps cut up a bowhead whale caught by Inupiat subsistence hunters on a field near Barrow, Alaska. Drawing on tradition, and keeping within the closely monitored Aboriginal subsistence whaling guidelines, a bowhead whale is carved and divided by a crew armed with knives and hooks, and then shared according to custom. (Photo by Gregory Bull/AP Photo)

In this Friday, March 28, 2014 photo, singers of the Moranbong Band, Jong Su Hyang, foreground, and Pak Mi Kyong, left perform on their stage in Pyongyang, North Korea. Step aside, Sea of Blood Opera. North Korean leader Kim Jong Un's favorite guitar-slinging, miniskirt-sporting girl group, the Moranbong Band, is back. And these ladies know how to shimmy. (Photo by Jon Chol Jin/AP Photo)

In this photo taken Tuesday, November 26, 2013 and made available Thursday, November 28, a Sumatran tiger leaps on Australia Zoo handler Dave Styles, left, as an unidentified man comes to Styles' aid in an enclosure at the zoo at Sunshine Coast, Australia. Styles who suffered puncture wounds to his head and shoulder was rescued by fellow workers at the zoo. He is recovering following surgery after being airlifted to a hospital. (Photo by Johanna Schehl/AP Photo)

In this Wednesday, March, 5, 2014 photo, Afghan female boxers practice at the Kabul Stadium boxing club, Afghanistan. The women, who are 18 and older, don't have much more than determination, and a trainer who runs them through their paces, watches as they spar, corrects their technique, tells them when to jab, how to protect themselves, when to power through with a left and then a right. (Photo by Massoud Hossaini/AP Photo)

In this April 12, 2015 photo, Sayed Ahmed Abdoh poles his boat to check his fish traps in the Nile River, near Abu al-Nasr village, about 770 kilometers (480 miles) south of Cairo, Egypt. Abdoh caught some 20 fish this day and gave them to his friend, Salama Osman, a migrant worker in a Cairo apartment building, to celebrate his biannual return to their village. (Photo by Hiro Komae/AP Photo)

In this Saturday, May 7, 2016 photo, Afghan refugee Shazia Lutfi, 19, peeks through the door of her room at the former prison of De Koepel in Haarlem, Netherlands. The government has let Belgium and Norway put prisoners in its empty cells and now, amid the huge flow of migrants into Europe, several Dutch prisons have been temporarily pressed into service as asylum seeker centers. (Photo by Muhammed Muheisen/AP Photo)

In this October 21, 2015, file photo, a young man rides a hoverboard along a Manhattan street toward the Empire State Building in New York. More than 500,000 hoverboards are being recalled after reports that they can burst into flames. The Consumer Product Safety Commission said Wednesday, July 6, 2016, it has received 99 reports of battery packs in the two-wheel motorized scooters catching fire or exploding that causing burns or property damage. The recalled hoverboards were made by eight companies. (Photo by Kathy Willens/AP Photo)