No it is not always for the third city, though for my savegame it will always be the third city. I have looked at other posts in this forum about crashes when people build a city in general, be it 1st, 2nd, 3rd, or 4th city. Something must be wrong in the code for founding new cities?
I have read others mention certain resources, like iron, may be the problem. Anyone know if it's true or what the problem is?