Don and Maxine Simpson from Bakersfield, California, died four hours apart on adjoining beds, holding hands during some of their final hours.
Melissa Sloan said her grandmother died first and when her body was removed from the room, her husband followed.
"All Don wanted was to be with his beautiful wife. He adored my grandmother, loved her to the end of the earth," she told KERO-TV.
He was 90 and she was 87, and they met at a bowling alley in Bakersfield in 1952, getting married in the same year.
When civil engineer Don worked for the US Army, the couple spent some time in Germany, where they adopted twin 18-month-old boys from an orphanage.
They returned to Bakersfield, where she worked as a nurse and he owned his own engineering firm.
They are survived by one son and five grandchildren.
Even in death, a couple married for nearly 62 years were inseparable.