LAWNDALE (CBSLA.com) — A Lawndale woman was heartbroken when she realized her engagement ring had slipped off her finger.

Miriam Castellanos said it wasn’t until a day later when she noticed she’d lost the ring, which had somehow fallen off her finger Saturday at a Costco gas station in Hawthorne.

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Luckily, an El Segundo woman was pumping fuel when she looked down and noticed something sparkling.

(credit: Jasmine Viel/CBS2)

(credit: El Segundo Police Department)

The good Samaritan took the ring home for safekeeping and immediately called police.

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El Segundo police officer Ken Cheng was on patrol when he got the call about the lost jewelry.

“On the way back to the station, I was like, ‘This looks like a real ring,’ ” Cheng said.

Cheng had the ring checked at a jewelry store near the police station and found out that it was valued about $15,000.

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Cheng said the jeweler found a serial number etched into the diamond, which detectives then used to trace the ring back to the couple.