Equipment Related Problems of the 2015 Ford E-350

Equipment problem

We have a 2015 coachmen freelander 21r RV (with a Ford f-350). Recently, while driving on the freeway a car near us kicked up some debris. This went under the RV and within 30-60 seconds after we heard a loud explosion/boom. My husband immediately pulled over and we were thinking it was blown front tire but just as he pulled over we noticed a large cloud of white "smoke. " the "smoke" turned out to be propane coming from our propane tank. Later he crawled under the RV and found a large hole in the tank. It appears that whatever hit it was hard enough to create a large hole in it and therefore causing the explosion. Fortunately, that was the only damage and no injuries were sustained. The reason for my email is that we were very surprised to see that there was no protective cage/rock guard around the propane tank to keep debris from damaging the tank. I personally think it's a design flaw and that any propane tank accessible from the side and but located under the RV should have some sort of protection around it. If that "cage" had existed, we wouldn't have experienced such a close call with a fire and possibly more. Thank you for your consideration.