Not sure why they did not go into a safe shutdown, it does take some time, but it could have been done before the power went out. So if they can’t go into a safe shutdown, who is approving their permits?
Seems that there is no safe shutdown once refrigeration is gone, except removal of the chemical materials, which can't be done in this case. That stuff will explode, simply unsafe to go near it. Sometimes crap happens and nothing can be done to prevent it.