It certainly sounds like your home environment is volatile. Your story is a familiar one, and we hear many parents ask if they have to wait until someone gets hurt in order to get help. Emergency rooms at hospitals typically will not admit a patient unless they are completely unstable at the time of assessment and are an imminent safety threat to themselves.
It sounds like your son has put you in the hospital. We don't know whether this was due to physical violence toward you that caused an injury, but you should ask police if you can press charges.
Another way your son might become involved with the law is through truancy. When he refuses to go to school, call him in as truant. Most states have laws stating that schools must report to the county attorney if a youth has missed so many days. This is often helpful because a court date is set and the judge makes a call on what the youth must do, so you would have another adult enforcing some rules.
If he leaves the house at night without permission or is not where he is supposed to be at any time, call him in as a runaway. This protects you if he gets in trouble for doing something while on the run. If he is an older teen, officers might not go actively searching for a youth, but with younger children, they often do. Officers will return him home or call a parent to pick him up if they find him.
You mentioned that your son will not participate in working with professionals, but just to get confirmation that he does not also have a mental health diagnosis, you should arrange for a full mental health evaluation. If you are considering placing him in a residential program, most programs would require a recent evaluation anyway.
Make sure your daughter has a safety plan when your son escalates. Can she run to a neighbor's home, call 911, or at least go behind a locked door? Let us know what type of services you are looking for, and we'll do our best to assist. Call in and speak to a crisis counselor who can search your local area for resources that you may not be aware of and which can be of help. If you are interested in the Boys Town Residential Program, the admission's process starts at boystownadmissions.org. There, you will find great introductory information, a video tour, and initial paperwork for admissions.