The Jamestown colonists had many risks to get to where they were. There wasn’t enough food/water supply for the abundance of people. The food/water they did have was mostly spoiled. Another reason, is sickness throughout the ships. Since it wasn’t hygienic or safe, many did get diseases. While many diseases were contagious a small number survived but were still very sick. You get on a ship full of people, for a trip of a couple of months. When you get off you might expect to be glad of finally being on land but when you come off to see plenty of dead people, you might ask yourself if the trip was worth it. Many people in Jamestown died of disease, there was no hygiene on the ships or the villages whatsoever. Being trapped