I was trying to get a URL for an article for you, but the webmaster hasnt completed that section.
But the issue of Divine fate and predestination is always a hot one and has been for many centuries as it is so intimately linked with other concepts (e.g Ajl min allah), which in turn all affect our accountability.
It was at the time when the Greeks entered the islamic lands, and started asking many questions to the muslim folk with regards to accountability. After all, if everything is the will of allah, then why are we sinful, and if everything isnt the will of allah, then why are certain events beyond our sphere of control?
And there are ayahs in the qur'an (sorry dont have the references with me) where allah relates to us about the issue.
Unfortunately, when the Greeks asked many inquisitive questions, and rightly so, the muslims presented a very 'reactionary' answer, which reflected a very confused debate rather than a proper uncovering of the truth, and therefore alot of the text you will find today, is based upon this confused debate, rather than a decisive confirmation of the truth. i.e it was a quick attempt on behlaf of the muslims to satisfy the questioner rather than to study the subject rigorously.
in very very brief terms, there are 2 points to be noted (and please note, im regurgitating this from memory, if i had the ayahs with me, that would make life easier).
Man has a sphere of control. Therefore any action he performs will always be within this sphere of control for which he is accountable. Such as killing someone with a knife.
But in life, we also face things (Qada) which are beyond our sphere of control, and these are which are Allah's will, for which we are NOT accountable. For example, if i was holding a knife in my hand, and someone was to accidentally fall onto my knife and die, then of course, im not accountable for that because it was beyond my control.
as i said, thats a very brief and quick overview of the concept.
But in response to your question, i.e are we accountable for the deaths in Iran, could we have made stronger houses etc?
Even if we had the strongest walls, if those people were destined to die, then they would, as its Allah's will (qada), however, the important thing to note is that, had we provisioned with appropriate measures, we would be rewardable for our efforts, and thus would be at peace that we did as much as we could within our sphere of control. After that, it would be 'unjust' of (astagfarullah) Allah (Swt) to hold us responsible for such a calamity.
A similar event that took place in Algeria, where many were killed due to the weak foundation. Now, Algeria is very close to the EU, and the EU suffers from no such problems. This isnt because earthquakes are uncommon in EU, but the rulers arent prepared to spend the money in Algeria to strengthen the foundations , so of course, allah(swt) will question them on the day of judgement, as being a ruler of a nation is a great responsibility.
The issue at hand then, is not a case of what can we do after an earthquake takes place and how much money can we spend in healing the lives of those that are broken, but what measures can we take to prevent such atrocities taking place in the first place.
and the answer to that is KHILAFAH !!!! - JOKE !!! (Sorry couldnt resist, seems like Khilafah is the answer to everything hai na? even toothache :p)
But on a serious note, our rulers (in general) have the money and the resources to plough their efforts in such a task, its a case of soceity waking up from her slumber and holding these people responsible for their lack of concern for the people they rule over...ke nahi?