Sorry to hear about your leak. I would definitely try to dry out the area the best that you can. Use a dehumidifier, if you have one or can rent one, and use some fans. I'd double check all of the water connections for the icemaker, as well as the water line itself. If the icemaker is turned off, I wouldn't think that you would get a water leak. While not on turkey day, our fun the day before Thanksgiving was having to replace our hot water heater. Fortunately, DW noticed the water on the floor around the water heater, before it had spread far. We spent most of the day trying to get a new one in. We bought one from Lowes, got it home, unboxed it, only to find that it was dented. So, we took it back and got another one. Thank heavens that it didn't happen on Thanksgiving day. We wouldn't have had hot water until today. When DW was at Lowes, returning the first water heater, there was a lady there trying desperately to find a new range, as hers had died. What is it about the holidays that appliances like to act up around? This post was edited by gpraceman on Fri, Nov 29, 13 at 13:19

OP: If you are still dealing with this issue - please look again at my original post. You need to understand if this is a system wide issue. If it is system wide, meaning that the plumbing is at the end of its life, you need to re-plumb and the only practical way of doing that is through the attic and side walls. Your flat roof will make this much more difficult. The good news is you can do it with PEX and fish some of the lines into place. You can consider pipe lining -- but if you have copper pipe that has reached end of life - I'd question how long of a fix that would be. It would be something to ask about if you go that direction. Copper plumbing has a lifespan of 50-70 years so 40 years is a little short if it was properly installed unless it was thinwall copper. Ground chemistry, water chemistry, even electrical currents, etc can shorten the lifespan. You may be able to see what type of copper -- K, L or M -- was installed if you can find a length of expose pipe with the printing on it. If it's type M - that's the thinnest type and I'd say you are at the end of life.

I know this is 4 years later but the missing grout is obviously why water has leaked under the tiles. Yes floor tiles will have the odd pinhole in the grout and also as you learned grout does absorb water and moisture/water does inevitably get under the tile but a large chunk like that would increase the amount of water under ur tiles. Even with weep holes, everytime your shower water will soak under the tiles and it'll never dry off. Your base is waterproofed but it'll also increase mold etc bc it'll never really dry. What I would've done was not use the shower until everything was dry. Maybe even use a shop vac and suck out as much water as you can from that one large area. Then regrout all the areas with holes and voids. But this would've been a potential temp fix as the entire grout job could've been bad and powdering if it wasn't mixed properly. I have mosaic floor tiles in my shower and I regret not getting larger ones because I hate all the grout lines. More grout lines means more maintenance and cleaning of it. 😑 But I do wonder how many people have shower floors that are constantly wet under the tile and not know it. I'm sure more people than not. Most people don't even realize whether or not their grout is in good shape or not. Btw. 4 years later, what did you end up doing?

Ok. I really appreciate the feedback. You seem very knowledgeable. It is insane weather right now in Michigan and I am trying to picture what they are going to do to fix the window right now. If your right and Anderson decides to take out the IG unit, is that something that impossible with 0 degree weather? Or does that mean they just order a new window itself? I guess I am just wishing this was all over and I didn’t have any more leaks. At least the rain stopped and it turned to ice for this week. I wonder what people do with water coming in. Do you think water is only coming in the sill area? Or do you think it’s actually in my walls? Thanks for any more thoughts.