The bigger point is: the company clearly is no position to threaten to fire people for making their own decisions about personal safety in situations like this.

The bigger point is: the company clearly is no position to threaten to fire people for making their own decisions about personal safety in situations like this. If anything, that simply adds to the anxiety, and amplifies risk. And unfortunately the situation appears to have been far worse than that: it wasn't simply that they were told they couldn't "flee" the premises -- they were expressly forbidden from taking at least some form of shelter, despite these supervisors almost certainly (I'd say 99 percent likely) had no training whatsover in directing these employees to safety in any way: Multiple employees of the Mayfield Consumer Products factory told NBC News that they took shelter in bathrooms and hallways when they first heard tornado warning sirens, then supervisors ordered them back to work when they mistakenly assumed the danger had passed.