Slightly off topic but the SCIF I worked in also had a vault. The vault was an office probably 18X20' that they had encased with 1/4" plate steel and added a huge bank vault type door. It was on the 3rd floor of the building and it was found that the engineer that calculated the weight loading screwed up his math. The whole corner of the building was sinking. We were required to measure, record and report the width of the cracks in the concrete block walls weekly. They did go in and add some structural bracing and the room below was changed from a classroom to storage.