I've been posting links to political errors and other contributors to the disaster in the politics forum because it feels like when there is a disaster, people deserve to have a safe place to go & this seems like the better thread for that.
I will say here that the stories coming out about potential contributors to the scale of this disaster--and there seem to be many different contributors, probably at every level of the response--remind me of A Night To Remember (about the Titanic). First, so-and-so doesn't put in enough lifeboats, then so-and-so doesn't answer the distress call, etc. All these things add up to more people dying. By themselves, some of these decisions may seem minor, but you put them together and the cost is so steep.
It will be up to the people who lost friends, family, and community members to determine whether or where to lay blame.
(And particularly considering that there are rich parents whose children are dead, I'd wager the odds are very high that someone--potentially many someones--will be sued. It is not always cheaper to do nothing).
Of course so much comes down to decisions people make now. What will they do to make people in the future safer? Deflecting doesn't help. Often blame does not help. What are they saying & doing now to make people safer? Some steps could be taken now. Some would require a lot more time and funding and should probably be done as well. It's not likely, given the pattern we've seen with flooding over the past decade, that the danger will subside again for as long a period of time as previously unless action also is taken to curb the risk.