John Smith warned the problem that the colonists only focused on finding gold. The colonists refused to plant or fish, so whe the food ran out, the starved. Worse still, the water they drank were contaminated which causes some disastrous diseases. By the winter of 1607, only 38 colonists survived.
When the second group came (600 people), they encountered the starving problem again, and only 60 of them survived.