A line chart visualizes the global cumulative total of COVID-19 deaths over time, with a horizontal marker line positioned at one million deaths. The chart uses React to render an SVG, with scales and line generation handled by d3.scaleTime, d3.scaleLinear, and d3.line. The data comes from a CSV file provided by the COVID-19 Data Repository at Johns Hopkins University, loaded via d3.csv and transformed by grouping daily death totals.