Many people recognize the alarm that sounds when an AMBER Alert interrupts local and national television and radio programs. Maybe you've seen the Alert notice on your cellphone.
It's an all-too familiar call for help, a missing child with only hours before the trail goes cold. Every second counts and the longer they are missing, the harder it is to trace them.
We all know what the AMBER Alert is, but many people of this generation don't know how it came to be.
It begins with a 9-year-old girl named Amber Hagerman. On January 13, 1996, Amber was grabbed off of her bicycle in a local grocery store parking lot.
Witnesses spotted a blue truck leaving the scene, but there were no more details about her abductor.
A neighbor who saw the incident called police, while Amber's little brother ran home to tell his family what had happened.
Learn how law enforcement and media responded to the abduction on Page 2
When Amber's father, Richard Hagerman and her mother, Donna Whitson (now Donna Norris) found out about their daughter's disappearance, they leapt into action.
Her parents called the news media and the FBI to report their daughter's abduction. Along with their neighbors and local police, Amber's parents searched for four days after the abduction.
In spite of widespread media attention and full national coverage, the search ended in tragedy when a dog walker found the little girl's lifeless body on the fifth day.
She was found with her throat slit, floating in a creek only a few miles from the grocery store.
What happened after Amber's funeral changed the fate of every abducted child in the future...
One day after little Amber's funeral, a Fort Worth mother named Diana Simone called a local radio station with an idea.
She was deeply moved by the family's loss and thought there must be something more that communities can do to catch abductors before it's too late.
Her idea was to create a system that allowed broadcasters to alert the public to missing children - much like they already did with severe weather.
In February, 1996, America's Missing: Broadcast Emergency Response (AMBER) was officially formed and named after Amber Hagerman.
The Amber Alert Program is used nationwide as well as in over 20 other countries. According to the National Center for Missing & Exploited Children, the startling warnings have led to the rescue of almost 800 missing kids.
As for Donna Williams, she still prays for justice to come to Amber's killer. It's been 21 years since the death of her daughter and the pain never really went away.
“I still want justice for Amber, but I can’t deal with everything right now,” she told Yahoo News, “I miss her a lot.”