My sister, cousins and I used to float down Henry's Fork on inner tubes when we were kids. Such great memories.

I had this same thing happen to me. In my case it was old cast iron pipes that had rusted through.

I would definitely suggest getting a plumber to check it out. You may also want to reach out to your insurance company. They wouldn't cover the cost of fixing the pipes, but they did pay to fix the damage to the ceiling below the tub.