What is the tone of the passage 'the wretches were set ashore not far from roanoke inlet, but by some fatal disagreement or laziness were either starved or cut to pieces by the native americans'?

I think the tone of the passage is: Mocking

Pay attention to the words by some fatal disagreement or laziness were either starved or cut to pieces.

From those words, we can conclude that The narrator conveys the 'wretches' died because of their own recklessness and stupidity.