Well because they're left with a charge of the children or elderly, they don't know how to swim, or simply because they never had basic resilience skills taught to them, like building a shelter, making a fire or even administering basic first aid.
Pues porque quedan a cargo de los niños o los mayores, no saben nadar, o simplemente porque nunca les enseñaron herramientas básicas de supervivencia, como construir un refugio, hacer fuego o incluso asistir en primeros auxilios básicos.