While they did have a skeleton crew they shouldn't have had, ratios like that are for normal operations.

In an emergency, taking a kid to the hospital takes priority - you're not gonna lose your accreditation or get fined for something like that... well, maybe soon under Abbott or Desantis but even then not yet AFAIK.

Otherwise you'd have to toss kids back onto the fire when the building's burning down if any of the teachers got stuck in. Which, again, entirely feasible with the legislators we have, but to my knowledge not law yet; even DeVos didn't manage to make that official.