there were no damages that I could see, quite a few feathers around, but when I looked at him yesterday I thought he was molting. I am a stay home mom so I see and hear what goes on with my birds. They are in the dining room and I am mainly in the living room, 1 floor of living space and I can see them anywhere I go. They were all getting along just fine.
Yes they are back in there old cages, certain birds don't roam the house. The cages are in the spot they used to be. I can check the temp, I have a thermometer I can put next to it. Here is a pic of the way it was set up with the stacker cage. The heat register is under the left half and the birds were in the top left and right and the bottom right half, there were no birds on the bottom left. The birds that died were the ones in the bottom right and 1 in the top right.
Would welding the bar have anything to do with it?

you can see on the left under the cage, the dark spot, that is the register. Of course this pic was taken before anyone passed on