So here we have a 4 storey single thickness block wall. You would think they would be banned in earthquake country.
In some of the nuclear plants we have a boatload of these 'Handyman Specials', which were block walls thrown in after the main construction. In Pickering A, we were forced to jack them up with steel, because of the seismic checking system we used. The other plants have never used this system.
That's one of the reasons that my favourite scenario earthquake, which is an M6ish earthquake in Hamilton will shut down all the nuclear plants. They will be a bitch to start up again, especially with block wall damage.