Police in New York are searching for Sandra Hall, a legendary singer with the hit group, The Platters, who vanished in Brooklyn.

As reported by The New York Post, the 80-year-old entered a subway on Friday at “Atlantic Avenue near the Barclays Center and Atlantic Terminal Mall.” She vanished shortly after 4 p.m. that afternoon.

Hall was with her niece, who also acts as her caregiver, when they were unexpectedly separated, according to Hall’s relatives. Hall then took an uptown 2 train and did not come back.

“She simply got on, and by the time my niece, her caretaker, gathered her bearings, the train had already left,” her daughter, Star DaSilva, explained, as per CBS News.

Family members reportedly said Brown has dementia, which causes her to become disoriented and confused.

According to NBC New York, Hall is noted as being 5 feet, 3 inches in height and was last seen wearing a pink shirt over a long-sleeve white shirt, alongside white shoes and gray pants.

“We don’t know where she’s been sleeping, what she’s been eating,” DaSilva added. “I’m very concerned.”

“My hope is that anyone who sees her photo or recognizes her will act as a good Samaritan and notify the authorities. She is cherished and we are deeply worried about her.”

Those with information regarding Hall’s location are encouraged to reach out to the NYPD’s Crime Stoppers Hotline at 1-800-577-TIPS, or to submit information through the CrimeStoppers website.

This is a developing story. Check back for updates.

[Feature Photo via NYPD Crime Stoppers]