What would you do?

Mindy and I are looking for advice and guidance. This week there was an incident where Kenya was "lost" and no one even noticed that she was gone. She had gone into the classroom bathroom and when she came out no one was in there. Unknown to her the class had left to the computer lab without her. She was scared and figured she would go home. When she got home no one was there, Mindy had gone to grandma's house. She totally freaked out at this point and went back to the school. She was later found by a teacher walking out front where Kenya had been sobbing hysterically. Mindy wasn't notified by a teacher, she found out from Kenya a half hour after school had been out. She went straight to the school and found the teacher eating lunch and the teacher said she was aware of what had happened and had forgotten to call Mindy. The next day Mindy went to the principal and then received a "it's no big deal" "it's happened with another student before" 2 minute talk. Mindy was rushed out of his office and told everything was under control. He also told her that it was the students fault for leaving school. Then I have also been noticing over Sadie's Kindergarten and now first grade year, that no one has ever asked for ID or who I am when I check her out of school. I don't frequent the school often enough to be known. I just sign her name and the time of check out and tell the secretary that I am picking up Sadie Gillman from so and so's class, no questions asked Sadie is sent to the office. The first week of school a note was sent home saying that the school will call home or the parents at work if the student does'nt show up for school. Sadie walks to school with two other kids from our ward. What if that walk were interupted and Sadie never showed? I kept her home from school two days because of illness and I was never notified that she hadn't gotten there. Obviously I knew where she was but they didn't know that. Mindy and I would greatly appreciate some suggestions or comments on the matter. We believe we are going to take this to the school board because some hairs need to be raised...