Collecting evidence: Try to collect and save all relevant evidence, including the proof of children's participation in school activities, photos or videos of children's accidents, and the school's response to this matter. For future use.

Communicate with the school: You can try to communicate with the school again, express your worries and dissatisfaction, and ask the school to give a clear response and solution. If the school ignores or refuses to admit responsibility, it can consider taking further action.

Seek legal advice: In this case, you can seek legal advice to know your rights and possible legal channels. You can consult a professional lawyer or legal adviser to understand the relevant legal provisions and ways to protect rights.

Report to the education authorities: report this matter to the local education authorities and ask them to intervene in the investigation. The competent department of education has the responsibility to supervise and manage schools, and should be responsible for the safety of students and the quality of education.

Contact the media: If you think it is necessary, you can also disclose this matter to the media to get more support and attention. Media reports can sometimes help push things forward and prompt relevant departments to take action.

In short, in this case, we should remain calm and take active actions. Try to maintain communication with schools and education authorities and safeguard their rights and interests through legal channels.