I get the idea of grabbing the things most important to you before you and leaving your stuff behind in favor of kids (I guess), but what I'm curious about is what caused them to cover the barracks in the first place.
I mean if you have got the time to cement over barracks for 1000 people surely you have time to pack up!
According to the article, the concrete floor was laid about 30 years after the artifacts were abandoned. If I understand it right, the fort had been raised and leveled more than once in between, so there was a thick layer of soil and debris between the floor and the artifacts at the time the floor was laid. The unknown question is why such valuable items were left the first time the fort was abandoned.
I suspect the artefacts weren't in a brick-and-tile building but a wood-and-thatch outbuilding, which after 30 years of abandonment would have collapsed and rotted over the contents.
I mean if you have got the time to cement over barracks for 1000 people surely you have time to pack up!