The blow out could be any fitting, connection, or hose.
Many builders use short lengths of flexible hose to connect appliances and bulkhead fittings to the PEC tubing inside. The connectors are sometimes hand tight threaded fittings that may come loose. The hoses themselves sometimes crack or burst.
Sometimes screw clamps are used. They can also come loose.
Frozen water lines can burst fittings and valves. Over stressed fittings can break.
I don't know how you would fix it with out digging in and finding the break. You need access to fix it.
Sometimes you can open an access panel under the shower or under a vanity cabinet. It is hard to work through those small holes, but it may save you from opening the bottom.
I wish you good luck and happy trails ahead!
Dutchman Kodiak Cub KD176RD 2018
Nissan Pathfinder 2015