I have to agree with others, it is very possible reports were filed.
It's been almost 25 years since i taught, but when I did, well, here were two examples:
a young teen boy, junior high. never knew Dad. Mom wqas in jail. Lived in a trailer without electricity or running water. Mom's boyfriend showed up once in a while (not sure if that helped or hurt). Sometimes did drugs himself. No adult at home 90% of the time. No adult the school could reach in an emergency. Every single one of us from the school had called and reporter---we all got told the same thing, that they were so understaffed that it was impossbile to help all the 4kids so they had to asume the teenagers could tke care of themselves.
Sisters aged 2 and 3. Mom had previously lost custody, but havingt left their father and taken some classesv the girls were returneed to her. Part of the bargain was tht they attend the daycare I worked at, court ordered to come at least three days a week (about a third of our kids this was the case)---essentially us daycare teachers were making sure the abuse stopped.
When Mom was with her boyfriend (who seemed to truly care about tge kids) the girls came in dressed in clean clothes with hair and teeth brushed, not starving, sometimes the talked about going to parks, etc (well the older one---the little one never spoke, she had issues, probably related to how she was treated). When Mom and boyfriend were on the rocks? The girls would wear the same clothes for a week, they'd come in on Moday with matted hair and food caked on their little faces usually revenous and eting tons of the food we served family style at meal times. We'd take photos, document, clean their faces, find other clothes they could wear while we washed their's, brush hair, etc. None of those calls over more than a year resulted in another remocal. There were no (new) cigarette burns on the girls, no bruises (we were asked every time) and they were brought to daycare so that was apparently good enough given the system in place and resources avaiolable at the time. it was absolutely heartbreaking to work with those kids and not be able to do more to help them.