How badly effected would Tehran be if it were hit by an earthquake?

[Zarda]

I thought all buildings in Iran are built to be earthquake-proof, or is it not? Is the government not regulating how buildings are made? Or does a building being earthquake-proof not really guarantee that it will be protected from a powerful earthquake?

I'm getting really scared about these new threats about earthquakes because I do not want something like what happened in Haiti to happen in Iran at all. It is so scary.

What is happening?