The shocking news came as Sanders was recovering from a heart attack he suffered last week, which forced him to temporarily suspend campaign events while he recuperated.
The 46-year-old Riggs reportedly died Saturday, two days after her diagnosis and the day Sanders returned to Vermont following his release from the hospital. She was suffering from neuroendocrine cancer, which causes rare tumors to sprout up on various parts of the body.
Riggs’ obituary says she worked as a neuropsychologist and frequently volunteered with pediatric hospice. She was married to Bernie's son Levi Sanders and met him while they both worked at a food shelter in Vermont. They had three children.
The obituary also states Riggs worked as the director of behavioral medicine at Dartmouth Medical School and was the owner of Riggs Geriatric Psychology.
Sanders received an outpouring of support on Twitter from media figures and his fellow political colleagues, including Sen. Marco Rubio, R-Fla., fellow 2020 presidential candidate Andrew Yang, and Meghan McCain.
Earlier, Sanders said he is recovering well from his heart surgery and plans to continue on with his campaign for the White House.