So that's where the water is coming from...

We keep getting a leak somewhere above the USR stage door. It's been a bit of a mystery till this week.

There was a major amout of water on the floor during a rain storm and I actually had enough time to investigate. Looking high and low and getting very confused.

Finally we opened a hatch into some ventalation ducting and this is what we found!
Mystery solved, just got to figure out what to do next...