I certainly hope those saints keep working because the way I read it, there is absolutely no hope or point to even consider any kind of 'preparation' for a major earthquake. Most of the city will collapse and so will what little infrastructure there is. There is really no point in trying to do anything beyond having helicopters drop food and first aid after it happens and have bulldozers make some roads into the city to see who and what is left.
Perhaps if the Pakistani government was more concerned with its citizens' health and safety, as in building regulations and so forth, rather than lining its own pockets and spending billions on nuclear bombs and other armoury, there was a good chance of actually minimising a catastrophe. As it is, staying the fuck out of Karachi seems to be the best preparation.