As 19-year-old gymnast McKayla Maroney described to an FBI agent in 2015 the sexual abuse she suffered at the hands of USA Gymnastics doctor Larry Nassar — excruciating details she hadn’t even been able to tell her mother — she began crying. At the other end of the phone line, there was dead silence. And then the words “is that all?”

The gut-wrenching testimony by Ms. Maroney on Wednesday before the Senate Judiciary Committee — and that of three other gymnasts — hit home how these young women were treated with disdain and dismissal by the people and systems that were supposed to protect them. It was yet another appalling reminder of how the sexual abuse of girls and women is not taken seriously. That Olympic champions were disregarded and left so vulnerable makes one shudder at how other victims with far less prominence are being treated.

“I don’t want another young gymnast, Olympic athlete or any individual to experience the horror that I and hundreds of others have endured — before, during and continuing to this day in the wake of the Larry Nassar abuse,” superstar gymnast Simone Biles testified as she fought back tears and had to pause. “To be clear, I blame Larry Nassar, and I also blame an entire system that enabled and perpetrated his abuse.”

The committee hailed the women who testified — who also included Maggie Nichols and Aly Raisman — and FBI Director Christopher A. Wray apologized for the failures of the FBI in handling the cases, which allowed Mr. Nassar to continue for more than a year to molest more than 70 girls and women under the guise of medical treatment. No question the women who testified showed great bravery. Ms. Raisman said it was hard for her to speak at the hearing, and recounted how after she first publicly spoke about her abuse, she couldn’t stand up in the shower and had to sit on the floor of the tub to wash her hair. There have been times since when she was so sick from the trauma that she had to be taken to the hospital by ambulance. “This might take me months to recover,” she said. “I just wanted to make that clear.”

These young women — and Mr. Nassar’s many other victims — deserve more than praise and apologies. They need answers. Who at USA Gymnastics and the U.S. Olympic committee knew about their abuse but ignored it or covered it up? Why did FBI agents seemingly go out of their way to protect a serial abuser? A scathing report by the Justice Department’s inspector general found that FBI agents involved in the case filed inaccurate reports and lied about their actions. Isn’t that cause for criminal prosecution? Justice officials declined to testify at Wednesday’s hearing.

The only person in jail is Mr. Nassar. He deserves to spend the rest of his life behind bars. But the exploitation of these girls and young women was perpetuated by many — not just one pedophile.