The 97-year-old twins, Jean Haley and Martha Williams, died after separate falls on the same night at their Barrington, R.I., home, police said. Police believe they died of hypothermia.
Later that night, the younger sister left, and authorities believe Williams may have tripped and fallen in the driveway as she walked out to her auto. Jean Haley managed to reach the garage, while Martha Williams remained behind to lock the auto.
NBC2 News reported that the two women had gone out to dinner with a younger sister, 89, on Friday night.
The women were discovered by a neighbour Saturday morning and rushed to the hospital where they were pronounced dead.
As police continue to investigate the weekend deaths of twin sisters in town, the police chief said it does not appear foul play was involved in the case.
The twin sisters were found 25 feet from each other, Martha Williams is thought to have fallen while walking to her auto in the bitter cold on Friday night.
It added that the cause of death is not yet known but "extreme cold temperatures that evening may have been a factor".
Police in Rhode Island believe it was a tragic accident that led to the death of two elderly twin sisters. All three went to Haley's Opechee Drive home at about 8:30 p.m.
According to the Providence Journal, Haley may have been a widow for more than 20 years. Police said she might have tripped on a rug.