I think in this case, the plastic wrapping of the tank actually caused the fatality of those fish. I think the “bad” air got into the tank and since it’s wrapped up, it takes longer for it to escape. Not to mention the low level of oxygen being wrapped up like that.
It’s too late now, but I wonder if it would’ve been better to cover the tank with a piece of plywood or something flat to prevent the dust and debris going in the tank while the work is going on. Then take it and leave the skimmer off when the work is done with open windows and/or fan running to circulate clean air into the room.