The article gives hardly any information. Clearly what they did was wrong, but child slave labor isn’t what I would label this without further information. The only minor discussed in the article was a 16 year old from another event that gave them reason to ban people under 18 from working in meat packing plants saying they are more dangerous.
The local who did comment said that kids worked second shift so they could work around their school schedules. Implying the kids are going to school, which more than likely rules out the slave part.
The company should get hit HARD for breaking labor laws and putting minors at risk of injuries. Had those same minors been working down the street at the movie theater or such, it may have been completely legal.
The raid happened at 9pm, and labor laws for minors limit working hours till 11pm (in Ohio)