One by one, over the course of a week, more than 150 women and girls stood up in a Michigan courtroom and confronted Larry Nassar, the disgraced physician who sexually abused them.

Nassar’s victims were athletes from elite programs, including USA Gymnastics. Their stories were painful, their courage was inspiring, their numbers a testament to serial failures by adults who were supposed to protect them.

“Your abuse started 30 years ago,” Aly Raisman, an Olympic gymnast who competed in London in 2012 and Rio in 2016, told Nassar. “But that’s just the first reported incident we know of. If over these many years, just one adult listened and had the courage and character to act, this tragedy could have been avoided.”

That was more than a tragedy. It was a betrayal.

Nassar, who was sentenced Wednesday to 40 to 175 years in prison, will spend the rest of his life behind bars. But his victims and their parents are left to wonder why this went on for so long. Where was Nassar’s supervision at USA Gymnastics? Or at his other employer, Michigan State University?

Nassar joined the USA Gymnastics medical staff in 1986 and, according to news accounts, left quietly in 2015 after a sexual abuse allegation. The organization didn’t immediately contact law enforcement. It did pay $1.25 million to settle a complaint by Olympian McKayla Maroney. The settlement was hidden from the public — including potential future victims — with non-disclosure and non-disparagement clauses intended to keep Maroney silent.

It appears that USA Gymnastics’ primary concerns were protecting its finances and reputation and maintaining its high profile on the international stage, rather than the well-being of the girls and young women whose athletic achievements gave the organization its luster.

The allegations against Nassar finally became public in 2016 when a victim spoke with the Indianapolis Star, though some victims say they complained decades earlier. There now are upwards of 100 lawsuits, pending investigations and overdue calls for USA Gymnastics to be decertified as the governing body for gymnastics in the United States. Hours after Nassar was sentenced, the president of Michigan State University resigned.

The parallels between the abuse in the USA Gymnastics program and in other organizations, including the Catholic church and Penn State University’s football team, are obvious. It’s also obvious — and infuriating — that lessons of these past scandals have been ignored.

Foremost among them is the responsibility of adults for vulnerable children.

From travel teams to elite Olympic training programs, thousands of youngsters participate in sports programs that take them away from home, sometimes for extended periods. Many parents fret about the time, pressure and potential for serious injury that go along with dreams of college scholarships or Olympic medals.

The crimes committed by Larry Nassar, and the decades that passed before anyone stopped him, are a nightmare for parents of aspiring athletes — and proof that more vigilant supervision is needed so that there will be no more victims left, like Aly Raisman, to ask why no one listened.