This project is the second assigment of the Coursera lecture "Reproducible Research" by the John Hopkins University. In this project, we will consider data from the U.S. National Oceanic and Atmospheric Administration (NOAA) database in order to answer two questions: - Across the United States, which types of events are most harmful with respect to population health? - Across the United States, which types of events have the greatest economic consequences? We will first consider the data and explain how it is transformed, we will then present the results and short conclusions. This project was carried out on Tuesday Nov 12, 2019, using RStudio with R markdowns.