This visualization, titled Hfailure, displays a hierarchical tree representing patient mortality data, showing a decision path from a time threshold to serum sodium levels and ultimately a "Death event." The tree also branches into geographic regions like Western Asia and Eastern Asia, with country-level leaves. Built with D3.js v5, it uses the `tree` layout, `linkHorizontal` for curved paths, and SVG rendering. Text size scales inversely with depth, and a zoom behavior allows interactive panning and scaling. Data is loaded from a local JSON file.