HAYWARD (CBS SF) — Hayward police have re-energized their efforts to find out what happened to Christine Eastin, a local teenager who went missing after a shopping trip to Mervyn’s in 1971.

Investigators took to Facebook on Wednesday, asking for the public’s help in obtaining any information about Eastin’s disappearance and offering a $50,000 reward in the case.

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On the night of Jan. 18, 1971, Eastin — then 19-years-old — called a friend asking her to go shopping at Mervyn’s. The pair spent the evening at the store, buying a pair of boots before heading home.

Eastin dropped her friend off, went home and then stopped by a local car wash to clean her boyfriend’s car before picking him up at work. She was never seen again.

The following morning the car was discovered at the car wash, still dripping wet, but there was no sign of Eastin.

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“Her sister, her friends and I we believe that there are probably a few people if not more who know what happened still,’ says childhood friend Judy Verhoek.

Judy got a call from Christine’s mother the night of her disappearance that she remembers to this day.

“I think about that night is that her mother called late at night and I’ll always hear her voice. She was frantic and asking if I knew where Christy was. Even though I was half asleep, I remember telling her that I didn’t know where she was, but I was sure she’d be home soon.”

“It has been 49 years since she disappeared,” Hayward police said in their Facebook post. “But this will remain an open investigation until we can bring long sought answers to Christine’s family. To achieve this goal, we have a dedicated detective assigned to this investigation.”

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The Hayward Police Department requests that anyone with information of what happened that evening contact Detective Sprague at 510-293-7176. He requests you contact him even if you have spoken to the police in the past regarding this case.