The answer to this is, to a large degree, a matter of personal opinion. Conditions that constitute a crisis in the mind of one person may not seem to be so dire to another person. My own view is that the biggest crisis in the juvenile justice system today is a lack of funding that would make it possible to house juveniles in appropriate facilities with appropriate programs.
The purpose of the juvenile justice system is to rehabilitate juvenile offenders. Young people who commit offenses are not typically as hardened in their ways as older adult criminals. This means that they are more susceptible to being rehabilitated. This idea is at the foundation of our juvenile system and is, indeed, the very reason why we have such a system. If our juvenile system is underfunded to the extent that juveniles are being housed with adult offenders and/or to the extent that there are not many programs to help rehabilitate them, we have a crisis.
This is what appears to be the case in the United States today. The juvenile system appears to lack the resources that would be needed for true rehabilitation of juvenile offenders. Therefore, it risks becoming an institution in which juveniles are simply warehoused in conditions that are more likely to cause them to reoffend. The system is failing to do enough to rehabilitate them. This is, in my view, the major problem facing the system today.
There can be many issues associated to this but one may be funding based on the fact that some juveniles don't get proper housing or food. There are less resources and more areas where improvement is needed.