Building codes influence the death tolls significantly. As older structures are phased out, the new structures put in, the chances of catastrophic building failure go down. I'm sure the building codes for the areas with massive casualties are nowhere near the requirements here.
Simple facts. Dealing with the codes for existing equipment, and seeing the changes occurring now, the requirements are much higher compared to 15 years ago. But the flip side is that due to computer engineering, it will go exactly to the code, but .001g higher and all bets are off.
I have noticed that most major code revisions go into effect after a significant seismic event that causes widespread death and destruction.
The death issue causes politicians to ignore building owner lobbying groups, because you if lobby on top of the bodies of former voters, while the insurance industry pushes the issues of losses, putting the responsability of future loss prevention on the policyholder.