What it takes to survive - article in the Sunday Times using similar references to the Horizon programme discussed here a few months ago, concerning interviews with survivors of Zeebrugge, Kings Cross etc.
I found it a bit muddled, saying different things at different times, but there are some interesting ideas. Part of it seems to be saying that in a crisis, some people enter a state where they are neither panicked, nor given up, but are somehow unable to process what is happening around them effectively. This may be because it is outside of their experience; they can't get a purchase on what's happening. In some cases this leads to denial, and attempting to follow their normal routine even though that's inappropriate and can lead them further into danger. In some cases it leads to "negative panic" or "brainlock" where they freeze up and don't know what to do at all - even if it's obvious and someone else is telling them. Tunnel vision is claimed to be a part of this, leading to a lack of situational awareness.
The article follows this with some comments about not giving up, but it sounds to me as though this brainlock isn't the same as giving up. Nor is it the same as denial.
It also goes on to talk about the importance of having a plan, eg to deal with an aircraft crash. For me the article crystallised the notion that much of the value of having a plan is not so much in the plan itself, as in the mental state it imbues. If you've at least thought about the disaster in advance, your brain is more likely to process it appropriately when it happens. Although I doubt anything is guaranteed to work. The article mentions people having the necessary knowledge but not being able to access it.