Definition of "heartbreaking"

Things went well with the clearing on Friday, but by Saturday, February 3, a 70 m.p.h. blizzard set in, and against such heartbreaking conditions, although an effort was made with the plough to keep open the sections cleared on the previous day, ground was gradually lost, [...].

1941 April, “Notes and News: Railwaymen and Snow”, in Railway Magazine, page 177

One could argue that Eliot's "great heartbreakings" were the overt physical signs of the inner psychological transformations achieved through brainwashing, cultural attack, and epidemic mortality.

1999, Karen Gayton Swisher, John Tippeconnic, Next Steps: Research and Practice to Advance Indian Education, page 17