Philippa Ross of the U.N. Women’s multi-country office in Fiji write about how women are impacted when tsunamis, cyclones and other natural disasters hit their communities. Age and gender are the two most powerful determinants of survival during a natural disaster. Oxfam carried out a household survey in Aceh, Indonesia following the 2004 Indian Ocean tsunami and demonstrated that up to four women died for every male in the most affected areas. Despite its critical importance in developing effective humanitarian disaster response, the collection and analysis of sex and age disaggregated data is routinely neglected. Photo credit: Kim Kyung-Hoon/Reuters