Ethiopian Airlines female pilots prepare the plane before takeoff at Bole international airport in the capital Addis Ababa, November 19, 2015. Ethiopia Airlines on Thursday, dispatched its first ever all-female operated flight. Every aspect of the journey was handled by women, from the ground crew, aircraft maintenance to traffic controllers. Gualu and her co-pilot were charged with flying the crew and passengers to Bangkok, Thailand. (Photo by Tiksa Negeri/Reuters)

A protestor makes a selfie in front of a burning car during a national trade union demonstration in Brussels, Thursday November 6, 2014. Tens of thousands of demonstrators are converging on the Belgian capital to protest government policies that will extend the pension age, contain wages and cut into public services. (Photo by Geert Vanden Wijngaert/AP Photo)

Rescue workers help the injured at the site of a multi-storey building collapse in the capital Nairobi, Kenya Sunday, January 4, 2015. The residential building in the Huruma neighborhood of Nairobi collapsed on Sunday and according to the Kenya Red Cross, a dozen people have so far been rescued but an unknown number are still feared trapped. (Photo by AP Photo)

In this November 2, 2017 photo, Mathew Fulkerson and his wife Leigh Ann pose at their Subterra Airbnb located in a former underground missile silo base near Eskridge, Kan. It was designed to house a nuclear warhead six decades ago – but now, this Cold War silo is the perfect spot for a mini break at just $133 a night. (Photo by Thad Allton/The Topeka Capital-Journal via AP Photo)

Members of the public interact with “Impulse” by Lateral O ce and CS Design during Lumiere London festival of light 2018 on January 18, 2018 in London, England. Lumiere London is a four night long light festival spanning the British capital with more than 50 artworks by UK and international aritsts. (Photo by Dan Kitwood/Getty Images)

An armed youth loyal to the Houthi movement takes part in a protest against the Saudi-backed exiled government deciding to cut off the Yemeni central bank from the outside world, in the capital Sanaa, Yemen August 25, 2016. (Photo by Mohamed al-Sayaghi/Reuters)

A police officer detains a woman on suspicion of collaborating with the 18th street gang during a "Safe House" operation at the Concepcion neighbourhood in San Salvador, July 2, 2015. Salvadoran police make “Safe House” operations at dangerous neighbourhoods of the capital to prevent murders, according to local media. (Photo by Jose Cabezas/Reuters)

People stroll alongside one of the hills of the Tio Pio park in Madrid, Monday, January 25, 2016. The park is a high viewpoint frequented mostly by locals due to its view of the Spanish capital skyline. (Photo by Francisco Seco/AP Photo)