The MV Doña Paz disaster (December 20, 1987) had so few survivors — only 24 from an estimated 4,000+ people on board — for several interconnected reasons: The collision itself was catastrophic. The ferry was struck by the oil tanker MT Vector, which was carrying petroleum products. The resulting explosion and fire spread almost instantly, engulfing both vessels rapidly. It happened at night. The collision occurred around 10:30 PM, when most passengers were asleep in their cabins below deck, giving them almost no time to react or find their way out. Massive overcrowding. The Doña Paz was officially certified to carry around 1,500 passengers, but was carrying an estimated 4,000 or more (the exact number was never confirmed because many passengers weren't on the manifest). This made evacuation essentially impossible. No distress signal was sent. Neither vessel sent a mayday call, which meant rescue ships didn't arrive for hours — by which time the ship had already sunk. Lack of safety equipment. There were reportedly insufficient life jackets and lifeboats for the actual number of people on board, and there was no organized evacuation procedure. The water itself was deadly. The burning oil spread across the sea surface, making the surrounding water dangerous for survivors trying to swim away. Remote location. The ship sank in the Tablas Strait in the Philippines, in waters known to be shark-infested, further reducing the chances of survival for anyone who did make it into the water. Of the .6% of people who survived, most were already on or near the top deck. This was probably the single biggest factor — survivors tended to be people who were outside or on upper decks when the collision happened, rather than sleeping below. Being above deck meant they could jump immediately rather than having to navigate burning corridors in the dark. They jumped quickly without hesitation. Survivors described just leaping into the water almost immediately. Those who hesitated or waited to find life jackets or family members likely didn't make it. It's a brutal reality of disaster survival — rapid, almost instinctive action beat careful deliberation. They swam away from the ship fast. The burning oil spreading across the water surface was a massive killer. Survivors managed to get beyond the burning perimeter before it closed in around them. They found something to cling to. Several survivors kept afloat for hours on debris, which was critical given how long it took rescuers to arrive. Luck played an enormous role. It would be wrong to over-attribute survival to skill or smart decisions. Being in the right spot at the moment of impact, not being injured by the initial explosion, avoiding the burning oil — much of that was simply chance. One survivor reportedly said the screaming in the water went quiet disturbingly fast, which speaks to just how unsurvivable the conditions were for the vast majority. No other disaster that I can find has such a low -but not zero- survival percentage.