How vulnerable it is. it is impossible to tell by looking at it. so, there is going to be an expensive evaluation that will need to be done for many of these buildings to find out just how vulnerable they are. so, structural engineers will need to go into each one of these buildings and potentially open the walls and see through a very detailed analysis what the vulnerabilities are and whether inexpensive retro fit is going to need to be required. that was my question. if they think it is going to be expensive to get into them and see which ones need fixing, what is the potential for how much it could cost to fix them? well, we re looking at billions of dollars in costs that are going to be spread probably over 20 years or so, maybe more. and the expense is really quite extraordinary once the building owners have started to look at these and structural engineers have laid out plans. they re talking about perhaps ....