Goljan said although fat embolism is usually from fractures of long bones, it can be caused by decompression sickness. Thought that was just nitrogen bubbles (air embolism).
Only young people or myeloproliferative disease (polycythemia) have predominantly red marrow. Adults tend to have more white marrow (fat). Caisson means bones start cracking and the fat inside will leak out into tissues/vasculature. Boom! Fat embolism.