This interactive bar chart visualizes the frequency of collision details in car accidents, ranking causes from "Other Motor Vehicle" down to "In-Line Skater." Users can click buttons to add or remove bars, revealing progressively less common crash scenarios. Built with D3 v7 and React, the visualization uses `d3.scaleBand` and `d3.scaleLinear` for axes, with SVG rectangles and animations updating the chart dynamically. The data is hardcoded in JavaScript arrays, with axis labels and rotated tick text styled via CSS.