A FORMER ALL-AMERICAN SWIMMER KEPT QUIET ABOUT YEARS OF SEXUAL ABUSE BY A TRUSTED FEMALE TEACHER - CAN SHE NOW GET HER TO ADMIT TO HER CRIMES? "48 HOURS: KRISTEN'S SECRET" - SATURDAY, OCT. 18, 2014

Tormented by horrific memories of being sexually abused years before by a middle school gym teacher, Kristen Cunnane thought about killing herself. But then she decided to fight back. In 2010, now a married and a successful college swim coach, Cunnane reached out to police to report the abuse.

The decision to fight back would change her life and, as she would soon learn, the lives of others. Tracy Smith and 48 HOURS report on Cunnane's quest to put her life together and track down her abuser in "Kristen's Secret," to be broadcast Oct. 18, 2014 (10:00 PM, ET/PT)
on the CBS Television Network.

"It was a big and scary secret that I had been able to block out for more than 10 years," Cunnane tells 48 HOURS.

"I was just shaking in bed at night and having nightmares," Cunnane adds. "I had to break that silence."

Little did Cunnane know she was not alone, and by speaking out, she gave three other women at the same school the strength to come forward. All three had been sexually abused in the same time period - the mid-1990s - by a different teacher. One of those victims spoke with 48 HOURS. "Kristen's story opened up a door to everything that has happened to me and so many other girls," says Jane Doe, who agreed to speak with 48 HOURS provided her name or face not be used.

An estimated 7% of middle and high school students are the targets of sexual abuse by teachers and coaches, representing millions of victims, according to the most recent study commissioned by the U.S. Department of Education, Smith reports on "Kristen's Secret."

Cunnane's story starts in 1994 when she was a student at Joaquin Moraga Intermediate School in Moraga, Calif. Cunnane caught the eye of gym teacher Julia Correa. They became close friends. Two years later, the 28-year-old Correa began her abuse of the 14-year-old Cunnane with a kiss. Cunnane says she was repulsed, but felt powerless to do anything about it. The awkward kiss was the start of years of abuse by Correa, who introduced Cunnane to sex, she says. "I remember being so young and not understanding what she was doing that I was really worried she could get me pregnant," Cunnane tells Smith.

The coach became increasingly obsessed with the young girl. So much so that the teacher would slip into Cunnane's home before the youngster got home and hide for hours in the closet or under her bed.

"I just felt this grab around my ankles," Cunnane recalls. "I like lost my breath and shook, like shook. She abused me in like every way she could have - I was just paralyzed with fear."

When Cunnane arrived home, the teacher forced her to have sex in her childhood bed while her parents slept down the hall.

Cunnane estimates there were hundreds of incidents of sexual and mental abuse over Cunnane's first three years of high school. But as a senior, Cunnane's life changed for the better when she began dating classmate Scott Cunnane. Thanks to Scott's love, she felt empowered enough to tell Correa to get out of her life. Correa tried to contact her a few times after that, but ultimately moved to a different state and had two sons.

Cunnane moved on, too, marrying Scott, now a prosecutor, and suppressing the memories until she could suppress them no longer. That was in 2010. The memories returned with such an intensity Cunnane knew she had to finally tell Scott her long-buried secret. "He said, like, 'I love you. We're going to get through this, and we have two options,'" Cunnane says. "'We can find her and kill her or we can go to the police.'"

Cunnane decided to go to the police, who asked her to call Correa and attempt to get her to confess to the abuse on recorded phone conversations. Could Cunnane pull off the sting? And could she get past the memories that have haunted her? What she learned about her former middle school shocked everyone.

Because Cunnane broke her silence, the Moraga School District paid $18.65 million to her and the three Jane Does who filed civil lawsuits. The current administrators at the Moraga School District apologized to the women who were abused, and gave 48 HOURS a statement noting it has learned from past mistakes and is fostering "a new culture."

Smith and 48 HOURS tell her story through interviews with Cunnane and her husband, Cunnane's mother, a childhood friend, attorney Dave Ring and others. 48 HOURS: "Kristen's Secret" is produced by Paul LaRosa. Deanna DiMuro is the field producer. Bruce Spiegel is the producer/editor. Peter Schweitzer is the senior producer. Susan Zirinsky is the senior executive producer.

Chat with members of the 48 HOURS team during the broadcast on Twitter and Facebook. Follow 48 HOURS on Instagram.