This example shows how to load and summarize COVID-19 case data from a CSV file using React and D3. The code fetches a May 2020 dataset from a GitHub gist via the `d3.csv` method, then displays basic metadata about the file, including its size in kilobytes, number of rows, and number of columns. The React app manages the loading state with the `useState` and `useEffect` hooks, rendering a loading message until the data arrives and then presenting the computed statistics. The visualization relies on `d3.csvFormat` to calculate the data size and ReactDOM to mount the component.