Deputies responded to the area of Gordon Road near Battle Trace Road just before 8 a.m. for a reported accident.
Police say a 2010 Kia Soul ran off the road, went down an embankment and hit a tree.
The driver of the Kia, William Leighty, 80, was severely injured and was admitted to Mary Washington Hospital's intensive care unit.
The passenger, Doris Leighty, 77, was pronounced dead at the scene.
Police believe William Leighty suffered a heart attack while driving, which caused the crash.
The accident remains under investigation and no charges are expected.