Woman encourages people to 'pay it forward' after the man who helped her died

When Jamie-Lynne Knighten learned that Matthew Jackson had been killed in a car accident, she immediately shared his story and encourage others to pay it forward.

As reported by NBC Sandiego, Jamie-Lynne, a Carlsbad resident, met Matthew at the Trader Joe's on Vista Way on November 10, 2015.

She was stuck in line with a crying baby and declining credit card at the time.

"[My baby] just wasn't having it. By the time we got to the check-out, I was done," Jamie-Lynne said.

Then Matthew stepped forward and offered to pay her $200 tab.

Jamie-Lynne said that the young man wanted one thing in return.

She said Matthew asked, "As long as you promise to do it for somebody else."

Jamie-Lynne realized that he wasn’t just being polite. He really wanted to help her.

The mother was very grateful and she even asked his name.

Jamie-Lynne also learned that he worked as a fitness trainer at the LA Fitness gym on Vista Way.

Though she only spent for about five minutes with Matthew, his act of kindness left a lasting impression on her.

Days later, she decided to call the gym to tell manager Angela Lavinder what an amazing person she had on staff.

That's when Jamie-Lynne learned some tragic news. Less than 24 hours after their remarkable encounter in a grocery store, Matthew was dead.

According to a report released by the San Diego County Medical Examiner's office, Matthew was killed when his vehicle struck a tree on November 11, 2015. Meanwhile, his two friends in the car survived.

For Jamie-Lynne, to hear that the person who impacted her life was gone was very heartbreaking.

According to her, Matthew didn't die in vain. She sees his story as a rare example of positive news that could inspire others.

Jamie-Lynne also wanted her children to recognize that there are still good people out there.

To honor his legacy, Jamie-Lynne said that efforts are underway, and they include encouraging other people to pay it forward.