Younger Brother with Autism, jumped out of the back of a school bus. Can we Sue?

Alright, So yesturday I was told by my mother that my younger brother, Liam, whom is 14 years old and has Autism, was riding the special ed school bus to his school. They had asked one of the teachers to follow the van, just in case anything happened. About 1 mile from our home, my younger brother unlatched himself from his saftey harness, crawled over 2 seats, and jumped out the back of the van. Had the teacher not stopped and chased him, he might not be alive. The van he rides on has 2 "monitors" sitting with the children. 1 of the monitors is a legal midgit, my brother is 180 pounds, and could easily get away from this woman. The monitors did nothing to stop my brother and he jumped out of the van. I was shocked when I heard this news and we thought legal action should be taken, for not being able to take proper care of my brother, and allowing him to jump out of the back of the van. I need some serious legal help, and would like to take this company to court. Thanks a lot