We had a similar experience with our HTT while in storage. One day my son and I were biking by the storage lot and noticed the door to our HTT was wide open. I stopped in and found the door lock had been busted. I had only put on the lock, not the dead bolt. We had nothing of interest to a non-camper. We figured they were just looking for something to steal.
Since the main lock was broken, I locked the deadbolt. About a week later, the storage lot manager called to say that it was broken into again. They couldn't get past the dead bolt, but they sure tried. They broke the window on the door and ripped the door a little at the bottom of the window. Since they couldn't get in, they broke the tongue lock and snipped the tether for the gravity feed cap.
I checked the only other camper in the lot, it too had been broken into. The police figured they were just looking for a place to stay.
-Michael