Grameenphone, a Bangladeshi Telecom company, pooled anonymized mobile CDRs and other data to analyze population movements before and after a climate-driven extreme event, Cyclone Mahasen, which affected 1.3 million people when it struck the southern districts of Bangladesh in May 2013. The project brought together relevant Bangladeshi ministries, telecommunications industry leaders, and the research and disaster response communities to improve the response to future extreme weather events. It is a first-stage project in a longer-term initiative.