A woman fills her hand with salt during a meditation session at a salt cavein Cairo, Egypt, November 14, 2016. Picture taken November 14, 2016. REUTERS/Mohamed Abd El Ghany

An internally displaced girl stands in a cavein the district of Khamir of Yemen's northwestern province of Amran May 9, 2015. Internally displaced Yemenis were forced to leave their homes in the nearby province of Saada amid Saudi-led air strikes. REUTERS/Mohamed al-Sayaghi

Elizabeth Caramol, 36, with one-year-old son Cavein on her lap and one of her older children, sits in a house in Marabut October 14, 2014, which they have rebuilt after Typhoon Haiyan swept away their old home in November 2013. Caramol was nine months pregnant when the storm hit and gave birth to a healthy baby boy five days after the storm, on the floor of a cave where they have taken refuge. Picture taken October 14, 2014. To match Feature PHILIPPINES-HAIYAN/SURVIVORS REUTERS/Thin Lei Win (PHILIPPINES - Tags: ENVIRONMENT DISASTER SOCIETY)