Complex sentence: The poem was apparently based on a true story of a boy's death whilst working in New England, whether the story is about someone Frost knew, or whether he heard about it second-hand via a newspaper article or other source is debatable.
Split into simpler sentences: The poem was apparently based on a true story of a boy's death while working in New England. Whether the story is about someone Frost knew, or whether he heard about it second-hand via a newspaper article or other source is debatable.