Reading a bit it seems to be potentially that the recommendations after the last big quake haven't been followed up properly. So basically stronger building requirements, with government validation was the plan; in reality not done (properly) and "checked" by paid companies.

My first thought on seeing some of the images was that there must be some criminal negligence involved. There is one area with 20 or so similar looking apartment buildings (about 6 levels each) where every second one has completely pancaked.

I was in Christchurch, New Zealand during the 2011 earthquakes. Only 2 major building completely collapsed. One had been designed by an engineer with insufficient qualifications and the other had design issues that were previously identified but never addressed.

It's worth noting in context that Erodgan is heavily involved in the Turkish real estate industry:

https://www.duvarenglish.com/amp/president-erdogan-the-world...