I work as a special education teacher but in Europe, not in the USA. This case of school shooting made me baffled when I read about the school's actions. I have only 7 years of job experience but in these years I have met many children with disabilities and with various mental health issues. Some of them changed schools several times until they got help they need. Many come from troubled families. This school for children with diagnoses of special needs has detailed procedures how staff should react in difficult situations, such as agressive or autoagressive behavior, a student who seems to be on drugs, bringing dangerous items to school, etc.
If a student is agressive or autoagressive, they must be taken from the classroom to another room where they stay with school psychologist. In the meantime, the principal, the nurse and parents are informed and if there is a risk of self-harm or harm to other students, parents are requested to take their child home. If parents cannot take the child home, like the Crumbleys told at school, the child in a bad mental state stays in a separate room with an adult. The principal may also decide to call the ambulance or the police if the situation demands it. All of the teachers are obliged to learn these procedures. We even had an active shooter drill though there has not been any school shootings in my country so far.
It is so difficult to understand for me that Ethan was sent back to the classroom as if nothing happened. A kid writes that he does not want to live anymore and two hours later no one cares. OK, Oxford High School is not a small special education school. But given the number of school shootings in the USA, the school should have done much better.