Mine didn't hit the ground, but I had a similar failure. Mine has the hose attachment where the tank is filled under pressure. I did as you did, hooked it up, let it run, when I heard water hitting the ground I went to turn it off and heard the frame work give way. I later figured out that it wasn't just a creak, the framework bent. I removed the frame, straightened it, welded in some stronger angle iron. Then I made a crude regulator out of two water hose adapters and a 90* ball valve. Now when I fill I can turn the water flow rate down.
In their infinite wisdom they don't restrict the flow coming in and even with a 45PSI regulator you can outrun the vent's flow rate pressurizing the tank.
I miss my old gravity fill setup.
Now-2014 Sierra 346RETS 5er BUB
Then-2002 Keystone Springdale 286RLDS TT
Nights camped in 2014-28, 2015-127, 2016-10