This example shows the global cumulative death toll from the early COVID-19 pandemic as a time-series line chart, with horizontal and vertical marker lines highlighting the 10,000-death threshold and the most recent date. Built with React and D3 v5, it uses `d3.scaleTime`, `d3.scaleLinear`, and `d3.line` to generate an SVG path, while custom React components render the marker lines. D3’s `axisBottom` and `select` handle the gridlines and tick labels. Data is loaded as CSV from a Johns Hopkins repository and transformed with `d3.csv` and `timeParse`.