Jenna Santos and Natalie Griffin were driving when their car hydroplaned off a California highway and into a swollen creek that night.
Unfortunately, only Griffin survived.
Santos' best friend Griffin was in the passenger seat and she noticed a way to escape from the sinking car through a broken rear window.
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"They were upside down and her friend was stuck and she tried to get her out, but couldn't so she got out and survived, but her friend didn't," said Kristina Galvin, high school student .
Santos couldn't get out of the front seat of the sunken car, but Griffin survived by holding onto a tree for 12 hours in freezing water.
Then on Thursday morning, Griffin was able to swim to a bank where she pulled herself out of the water, hiked up a hill, and flagged down someone passing by.
She told emergency crews where to find her best friend.
"She had so many dreams in life," Griffin said.
Santos planned to be a psychiatrist one day and was a cheerleader with lots of friends.
"She was so full of light and so energetic, there was nothing not to love about her, she never said one bad thing about anyone," Santos' friend Jessica Uhlenhop said.
Click here to help Santos' family pay for funeral costs.