The fatal crash occurred on Dec. 8 around 4 p.m. along North Country Road near Shore Road in Mount Sinai.
Police said 78-year-old Marylou Pinto was behind the wheel of a 2007 Kia and driving east on North Country Road when her car crossed over the roadway’s double yellow line and veered into oncoming traffic.
Her car, police said, collided with a 1997 Lexus that was being driven by Patricia Vallary, 68, of Mount Sinai.
Emergency crews rushed Pinto to nearby Mather Hospital, but she succumbed to her injuries and was pronounced dead by hospital staff, law enforcement officials said. Vallary, the other driver, was treated at Stony Brook University Hospital for non-life-threatening injuries. Her condition was not known Monday.
Sixth Squad detectives impounded both vehicles involved in the crash for safety checks. They said the investigation is still ongoing.
Anyone who may have witnessed the fatal collision is asked to call investigators at 631-854-8652 or anonymously call the Suffolk County Crime Stoppers hotline at 1-800-220-TIPS. All calls will remain confidential.
Andrew Tetreault contributed to this report.