Sen. Lindsey Graham, R-S.C., died of aortic dissection as a result of arteriosclerotic cardiovascular disease, according to reports citing the Medical Examiner of the District of Columbia’s preliminary findings. 

Fox News reported that the cause of death resulted from an aorta rupture related to hardening of the arteries.

Graham's office initially said early Sunday that he died after a "brief and sudden illness" at 71.