A 17-year-old Fairfax County student and her parents are suing the county school system, accusing officials of failing to properly investigate a sexual assault that allegedly took place during a band trip.

The district’s response was “flawed at every stage of the process” and created a hostile learning environment for the teen, according to the lawsuit, which was filed last week in the U.S. District Court for the Eastern District of Virginia.

The girl, a student at Oakton High School, said Fairfax County Public Schools exacerbated an already devastating situation.

“I was in fear,” the teenager said in an interview. “I was around my attacker and the administration that hadn’t done anything to help. . . . My grades were severely impacted, and I was just kind of miserable for a lot of the time.”

The Washington Post does not name victims of sexual assault without their consent. The student is identified as Jane Doe in the lawsuit.

The allegations emerge four years after the Fairfax school system entered into an agreement with the U.S. Department of Education to improve the handling of sexual harassment cases. That pact was prompted by an alleged sexual harassment case involving students.

Attorneys with Public Justice, a nonprofit legal advocacy group representing the girl, said the school system’s handling of the latest case indicates a systemic failure to comply with Title IX, the federal law barring sex discrimination in schools that receive federal money.

They are asking the court to declare that the Fairfax school system violated Title IX and for the district to pay the student unspecified monetary damages.

Schools spokesman John Torre said in an email the district had yet to receive the lawsuit.

“We take all allegations of Title IX violations seriously, investigate those allegations and take action where appropriate, including referrals to law enforcement for possible criminal prosecution,” he said.

In March 2017, the girl’s high school band took a five-day trip to Indianapolis for a band exhibition, the complaint says. The girl, who was 16 at the time, said a male student, who was a senior, sat next to her on a school bus during the trip there.

The lawsuit says the male student, who was not named in the lawsuit, covered the girl and himself in a blanket after saying he was cold. When it became dark, the male student allegedly moved his hand toward the girl. The complaint alleges he fought the girl’s attempts to stop him, grabbing the girl’s hand and forcing her to rub his genitals.

The male student allegedly penetrated the girl with his fingers after forcing his hand down her pants, and grabbed her breasts, the complaint says.

Shocked, scared and humiliated, the girl “suffered in silence,” according to the lawsuit. The teen, who did not report the alleged assault to law enforcement, became emotionally and physically ill during the trip, the lawsuit says.

The girl did not sustain physical injuries from the alleged assault that required medical treatment, but her lawyer said she has been in counseling to cope with emotional trauma. The girl did not report the alleged attack while on the band trip because she was traumatized and frightened, her lawyer said.

But the girl told four friends about the incident, two of whom reported it to school employees soon after they were told, according to the lawsuit. One of the friends told an assistant principal who was on the band trip, and the second friend, who was not on the trip, informed a math teacher, the lawsuit says. The friends are not named in the lawsuit.

A third friend told a parent after the trip, according to the lawsuit. The parent reported the incident to Jamie VanValkenburg, the band director, in a phone call, the suit says.

VanValkenburg referred questions to the school system’s Office of Communication and Community Relations. Torre, the school district spokesman, declined to respond to allegations made against individual school district employees.

[At Lake Braddock, sexual harassment accusations, personnel changes and lingering resentment]

The school system did not contact the girl about the alleged assault until she returned from the band trip, according to the complaint. On March 13, 2017, the girl was brought to an office with Jennifer Hogan, the school’s director of student services.

Hogan, according to the lawsuit, told the girl, “We have a report that you engaged in sexual activity on the bus.” The administrator allegedly told the girl to prepare a written statement. The student’s attorney provided The Post with a copy of the statement. Hogan referred questions to the school system’s communications office.

Another administrator, Wally Baranyk, the school’s safety and security specialist, allegedly asked the girl whether her parents planned to take legal action. He allegedly told the girl that filing a lawsuit would be a waste of money and that she would lose in court, the lawsuit says.

Baranyk referred questions to the district’s communications office.

The school system, the complaint alleges, conducted a “sham investigation” and did not notify the girl’s parents about its outcome.

“At first, I was just kind of relieved that I wasn’t going to get in trouble,” the 17-year-old said. “Now, it obviously makes me angry. . . . If someone hurts someone like my attacker hurt me, they should be punished.”

The school system did not notify the girl’s parents before questioning her, inform the girl of her rights under Title IX or support her as she coped with the alleged sexual assault, the complaint alleges.

Concerns have been raised before about the school system’s handling of sexual harassment allegations.

In 2014, Fairfax County Public Schools voluntarily agreed to reexamine its handling of sexual harassment allegations between students. The district did not admit that it had violated regulations. The agreement with the Education Department’s Office for Civil Rights laid out more than a dozen requirements that school system regulations must address, including who should field allegations of sexual or gender-based harassment, and requiring an investigation that is “adequate, reliable, impartial.”

An Education Department spokesman said the case against Fairfax remains open, and the agency declined to discuss how the agreement was being monitored or implemented.

The school system did not respond to a question about how or whether it has implemented changes as a result of the agreement.

Adele Kimmel, a senior attorney for Public Justice, said the school system “pays lip service to caring about sexual assault.”

“Fairfax County is a role model for what not to do when it comes to protecting victims of sexual assault,” she said.

The student alleging assault chose to file a lawsuit instead of a Department of Education complaint because she felt a lawsuit would result in more systemic change, Kimmel said.

After the alleged assault, the 17-year-old Oakton student said her mother found a counselor who specializes in addressing sexual assault. The student said she hopes coming forward will spare victims of sexual violence the experience she said she endured.

“It’s been a really long process,” the girl said. “If I can speak out and impact someone’s life or really change someone’s life and help them realize that they’re not alone . . . I’m doing what I need to do.”