Answer: They died as a result of disease, which they contracted from the europeans.
Step-by-step explanation:
At that time Europeans were traveling, and exploring. When they found the Americas they claimed it, not noticing it was already "claimed" by others (the native americans). Now, the native americas have never been exposed to diseases like the europeans had. the europeans brought goods, food, clothing, but also sickness. Natives had never encountered such diseases so many of them died, because their immune system was weak, and couldn't cope with small pox, and other diseases. That is why many native americans had died as a result of contact with europeans.