What factors caused many deaths in Jamestown in the beginning

Jamestown is the first English colony that got established in America. The weather in Jamestown was not congenial for the growth of millets, corn or maize.

Jamestown was geographically located near a swamp which bread mosquitoes. These infectious creatures caused malaria and typhoid. People of Jamestown were severely affected by prolonged illness. They settled in America thinking that they would gain Gold and other resources for their easy living but it was the other way round.

Starvation and famine were at its peak which compelled the population to hunt for food. People began to do the unexpected in order to appease their hunger.

Water in the lake was so polluted with grime that it was unfit to drink and it was salty. This made the settlers; survival difficult. Half of the settlers were dead due to diseases and Anglo Powhatan attacks.

"The first settlers of Jamestown endured the problems of hostile Indians, starvation, and poor leadership and government. Jamestown was the second English Colony in the New World (Roanoke being the first) and the Indians attacked the settlers within 3 days of arrival in May of 1607."

so maby the indians