As Haley's mother, Ronda, recalled, "The tiger licked her foot or something. It startled her and she squealed. And she turned, screamed and turned to run. And when she turned to run, it lunged at her and attacked her and got her by the back of the neck."
Haley died that day. And the 550-pound Siberian tiger was killed during a futile attempt to rescue her.
Haley's parents were shocked to learn that their daughter wasn't the first person to be attacked.
In the past five years, there have been 50 documented attacks by lions and tigers in the United States.
"20/20" went undercover to visit another one of these backyard operations, the "Siberian Tiger Conservation Association" in Gambier, Ohio.
Despite the fact that the U.S. Department of Agriculture had suspended and then revoked its exhibition license, "20/20" found the facility still open for business and willing to let paying visitors inside its cages for close encounters with lions and tigers -- under what the USDA has termed the "guise" of "educational training sessions."
"20/20" obtained footage of customers actually entering the cage and being encouraged to pet and hug the tigers. All seemed to be going well until, without warning, a tiger charged the man shooting the video, who suddenly found his leg between its jaws. Fortunately, the tiger let him go without breaking the skin.
Ten other people were not so lucky. That's how many people the were injured at this facility in one year, according to the USDA.
Haley Hilderbrand's parents are trying to make sure that what happened to their daughter never happens again. They have worked to get legislation enacted in their home state of Kansas that would restrict private ownership of big cats, and are now working on a national law, called "Haley's Act," that would strengthen the Animal Welfare Act.