Ammunition airlift into besieged Khe Sanh, Operation Pegasus, April 1968. (Photo by Larry Burrows/AP Photo)

A deserted alley in the ghost town of Apice, in the province of Benevento, southern Italy, 22 November 2016. After the Irpinia earthquake that took place in southern Italy on 23 November 1980, leaving at least 2,500 people dead, 8,000 injured and 250,000 homeless, the town in the heart of the Sannio area was evacuated and its residents moved into what has become the new Apice. Only recently the narrow streets and the tragically abandoned buildings have started, slowly, to repopulate. (Photo by Cesare Abbate/EPA)

The sign above the door of restaurant and hotel “Am Paulusbogen” is partially submerged in the flooded centre of the Bavarian town of Passau, about 200 km (124 miles) north-east of Munich June 3, 2013. (Photo by Michaela Rehle/Reuters)

A stray puppy walks along abandoned train tracks near the Chernobyl nuclear power plant on August 19, 2017 near Chornobyl, Ukraine. An estimated 900 stray dogs live in the exclusion zone, many of them likely the descendants of dogs left behind following the mass evacuation of residents in the aftermath of the 1986 nuclear disaster at Chernobyl. (Photo by Sean Gallup/Getty Images)

“A Brazilian hotel was evacuated in the capital, Brasilia, on Monday after a man took hostage an employee who was held for hours before he was safely released to police. Firefighters and police cordoned off the area and about 300 guests and other employees left the hotel – some reportedly told to leave by the man who took the employee hostage”. – Associated Press. (Photo by Evaristo Sa/AFP Photo)

Smoke and flames rise over a warehouse storing ammunition for multiple rocket launcher systems at a military base in the town of Kalynivka in Vinnytsia region, Ukraine September 27, 2017. Ukrainian officials say they have evacuated more than 30,000 people after a fire and ammunition explosions, at the military base on Tuesday. (Photo by Gleb Garanich/Reuters)

An abandoned protection masks in the deserted building near bypass channel for cooling at the Chernobyl nuclear power plant in the Exclusion Zone, Ukraine, April 5, 20177. The Chernobyl nuclear accident occurred on 26 April 1986 in the No.4 light water graphite moderated reactor at the Chernobyl Nuclear Power Plant near Pripyat. An estimated 47,000 people of the city of Pripyat were evacuated after the explosion in 1986. (Photo by Vitaliy Holovin/Corbis via Getty images)

A US Marine leads two Viet Cong suspects in restraints during the Tet Offensive on February 20, 1967. (Photo by Bettmann Archive/Getty Images)