Lisa Radogno, the daughter of Illinois Senate Republican leader Christine Radogno, died of a "massive pulmonary embolism," the Lemont lawmaker's spokeswoman said.
Lisa Radogno, 31, was one of three daughters of Sen. Radogno and served as an executive assistant in the Washington, D.C., office of U.S. Sen. Mark Kirk, a Highland Park Republican.
"To all my friends: Late today, my beautiful middle daughter, Lisa Marie Radogno, was called home," Christine Radogno wrote on her Facebook page.
"Her death was sudden due to a massive pulmonary embolism. We knew the news was not good all day but the finality is beyond painful," Radogno said. "Her Washington, D.C. friends have been fantastic. So great to see how much she was loved."
Funeral arrangements are pending.
Kirk took to the U.S. Senate floor to give an emotional speech calling Radogno "one of the brightest lights of our D.C. office."
Illinois Senate President John Cullerton offered his sympathies and other political leaders sent condolences via social media late Wednesday night and Thursday.
"I'm saddened to hear that my friend and fellow leader has suffered an unimaginable loss," Cullerton said.
"This is a tragic reminder that beyond our titles and positions, we are all mothers or fathers, sons or daughters."