>99% of people of in large cities (>500k) that experience prolonged and complete food loss will perish without massive measures taken by a number of people an order of magnitude greater than those effected. The Caribbean hurricanes are an excellent case study into the realities of dealing with a near complete breakdown in government. With some not insignificant work a model could be created from the volume of data readily available from numerous providers. One could then extrapolate a number of factors to consider and model when designing a persistence plan. Those living in rural areas are more likely to weather these crises as they are less reliant on modern infrastructure for minimally viable persistence.