Paramedics carry an injured woman out from a subway station after a rush-hour subway train derailment, to be transported by a medical helicopter in Moscow, Russia, on Tuesday, July 15, 2014. A rush-hour subway train derailed in Moscow Tuesday, killing 20 people and injuring at least 150, emergency officials said. Several cars left the track in the tunnel after a power surge triggered an alarm, which caused the train to stop abruptly. (Photo by Ivan Sekretarev/AP Photo)

Collided passenger train cars are seen in Taebaek, South Korea, Tuesday, July 22, 2014. Two passenger trains collided head-on in eastern South Korea on Tuesday afternoon, killing one passenger and injuring dozens, fire officials said. (Photo by AFP Photo/Yonhap)

A worker stands by a historic building as it is moved down the block on wheels on New York Avenue to make way for a new construction July 28, 2014 in Washington, DC. A team from Expert House Movers have been moving the historic building near 4th Street which is one of the largest structures in the DC area to be moved. (Photo by Brendan Smialowski/AFP Photo)

Palestinian female Hamas security officers demonstrate their skills during a graduation ceremony in the northern Gaza Strip, Wednesday, April 2, 2014. 1200 officers graduated from advanced training courses that lasted one year in Gaza police academy of Hamas. (Photo by Adel Hana/AP Photo)

In this undated handout photograph from the “Inside Out Project”, a poster bearing the image of a Pakistani girl whose parents, lawyers say, were killed in a drone strike, lies in a field at an undisclosed location in the northwestern Khyber-Pakhtunkhwa province. A group of artists in Pakistan are hoping to generate “empathy” among US drone operators by placing giant posters of children in the country's troubled tribal regions. (Photo by AFP Photo)

A three month old white Bengal female tiger cub looks around her enclosure at the Buenos Aires Zoo, Argentina, Wednesday, April 16, 2014. Cleo, a captive Bengal white tiger at the zoo, gave birth to two females and one male white tiger cubs on January 16, 2014. (Photo by Natacha Pisarenko/AP Photo)

Colleen Kelley, of Iowa City, Iowa, fixes the hat on her dog Bruce during judging at the 35th annual Drake Relays Beautiful Bulldog Contest, Monday, April 21, 2014, in Des Moines, Iowa. The pageant kicks off the Drake Relays festivities at Drake University where a bulldog is the mascot. (Photo by Charlie Neibergall/AP Photo)

Dancers of the Moulin Rouge cabaret adjust their boots prior to a show on April 22, 2014 in Paris. Since 1945, the “Maison Clairvoy” is specialised in the creation of luxury shoes and started in 1960 a collaboration with the famous Moulin Rouge to create boots and shoes for French Cancan dancers. (Photo by Franck Fife/AFP Photo)