Storing travel trailer in a metal building

I helpped an elderly gentleman pull his prized Nuwa Snowbird out of his 40X50 pole building with concrete floor. He sold his truck and after 2 years of sitting in storage he decided it was time to sell the camper. I hooked up and pulled it out in the driveway. We ran the slides out and went inside to find that everything was covered with mold and his custom hardwood floors had buckled and were destroyed. I though he was going to break down in tears it was so bad.

I know this is a rare case but just be warned to make sure you have plenty of ventalation and air moving around your trailer when it is stored indoors.