A burn victim's airways are black with soot — alive during the fire. Antemortem burns show soot in airways (breathed smoke), red inflammatory line at burn margins, and blisters with protein-rich fluid; postmortem burns are dry, yellow, waxy, no red line. Carboxyhemoglobin (cherry-red blood) confirms smoke inhalation. The airway's soot is the testimony — the victim breathed the fire, proving life during burning.