Question

Why were Narcissa and Marcus Whitman murdered by the Cayuse Indians?

Answer 1

The Cayuse tribe accused the couple of poisoning over half of their tribe. So some led an ambush, and the Whitman's were killed.

Step-by-step explanation:

Answer 2

When a measles epidemic broke out at the mission in November 1847, many of the Indians were killed while the white newcomers survived. The Cayuse suspected that the Whitmans and their foreign religion were the cause of the fatal disease. The Whitmans and eleven other whites were killed by the Cayuse, and the mission was burned down.