A tanker airplane drops fire retardant on a wildfire on September 1, 2011 in Graford, Texas. More than 6,500 acres and more than 45 homes in the area have burned since Tuesday as wildfires sweep through parts of Texas and Oklahoma. (Photo by Tom Pennington/Getty Images)

A publican serves a glass of stout to a donkey in the East End of London, 1960s. (Photo by Steve Lewis/Getty Images)

Smoke billows from Jinnah International Airport in Karachi, Pakistan, June 9, 2014. (Photo by Athar Hussain/Reuters)

Dust covered seats are pictured inside the lounge of the Jaisalmer Airport in desert state of Rajasthan, India, August 13, 2015. Two-and-a-half years after the completion of a new $17 million terminal building, the airport in Jaisalmer, a small and remote desert city in India's western Rajasthan state, stands empty. (Photo by Anindito Mukherjee/Reuters)

Passengers check their mobile devices as a bin is full of garbage during a protest by the cleaning staff at Barcelona's airport, Spain, December 1, 2016. (Photo by Albert Gea/Reuters)

U.S. Park Police work to keep people away from the area surrounding the Washington Monument after a 5.8 magnitude earthquake struck the east coast August 23, 2011 in Washington, DC. Police officers said that unidentified material had fallen off the Washington Monument as a result of the earthquake. All the monuments and buildings along the National Mall have been evacuated and closed. (Photo by Chip Somodevilla/Getty Images)

A sign is posted in front of the new Yoga Room at San Francisco International Airport's terminal two on January 26, 2012 in San Francisco, California. (Photo by Justin Sullivan/Getty Images)

A Palestinian boy holds an umbrella as he runs near houses that witnesses said were destroyed or damaged by Israeli shelling during the most recent conflict between Israel and Hamas, on a rainy day in the east of Gaza City November 16, 2014. (Photo by Suhaib Salem/Reuters)