This example visualizes COVID death percentages across U.S. states using an interactive pie chart built with D3 v4 in a React framework. The chart displays seven state values as colored wedges, with a custom tooltip that appears on mouseover showing the state name and its corresponding percentage, while the SVG-rendered arcs respond to hover by adjusting opacity. The code implements hover and touch interactions using D3 event handlers, and includes a legend generated from the same data array.