A sprinkler pipe had burst over the garage and sprayed throughout the entire house all day.
Fire Sprinklers? Rare in Single family homes here. Did the county require it for new construction? Maybe only the garage?
I built our last house with a full sprinkler system. Filled the system with eco antifreeze before the final charge, although I had no pipes in the attic, only basement and walls, but if we lost heat for an extended time I didn't want a busted pipe. Unlike your house water, the sprinkler lines should be the highest pressure possible and bypasses the regulator so you must have had a Noah sized flood and a HUGE water bill. We had 130psi.