Years ago I was a New Store Opening trainer for one of the major chains. I was acting as the prep trainer in this instance. At the time I did this all of the desserts were still baked on site and we were working on some of them that day.
When I was baking a carrot cake I used to set them on the maxi-rack with the lid of an 18x36 lexan cover on them so nothing coud get in the batter as it came to room temp.
Well it's amazing how clear a brand new lid actually is. Yep you guessed it. Two 18x36 pans of carrot cake when into the oven, lids and all, and started to bake.
After 20 minutes passed I went to go rotate the pans in thne oven and when I opened it...... Arrgghhh!
It seems when the lexan lid heatd it sunk and forced all or most of the batter out of the pans. It all had become one solid carrot cake oven racks, cake pans, oven deck in all. It was a good thing that only 2 of the 6 trainees were there to witness it.
It was really funny that when I returned to this company a couple years later and was opening more restaurants with them, there were still some opening team members I worked with that were told the story of this little mishap.