Lightning strikes the Willis Tower (formerly Sears Tower) in downtown on June 12, 2013 in Chicago, Illinois. (Photo by Scott Olson/Getty Images)

A person drags a suitcase as a boy clings to it on a square in front of a railway station ahead of the Chinese Lunar New Year in Qingdao, Shandong province, January 28, 2014. About 3.62 billion trips will be made during the 40-day Spring Festival travel rush, which started from January 16, reported Xinhua News Agency citing a government official. (Photo by Reuters/China Daily)

A model has her hair done before The Blonds Spring/Summer 2016 collection during New York Fashion Week in New York September 16, 2015. (Photo by Carlo Allegri/Reuters)

Two railway workers chat in front of a flower mural inside a subway station visited by foreign reporters during a government organised tour in Pyongyang, North Korea October 9, 2015. (Photo by Damir Sagolj/Reuters)

Two novice Buddhist monks walk alongside a basket seller to collect alms following a clerics rule of no footwear nor use of umbrellas in Mandalay, Myanmar, Friday, October 9, 2015. (Photo by Hkun Lat/AP Photo)

A leopard seal feeds Paul Nicklen a penguin. (Photo by Paul Nicklen/National Geographic). Antarctic Peninsula, 2011