I agree with SUPUTIN, there is no way a primer did that damage. I sweep around my loading area and put the dirt in my dust tin. Since there was some paper in the basket, the wife took it up and burned it in the fireplace. She told me there were some pops in the fireplace when she burned the refuse from the waste basket. I knew right away they were live primers, because I had spilled some on the floor and didn't get them all. They were just pops in the fireplace, and our fireplace has glass doors. So a primer going off in free space is a very minor event.
I spilled some powder on my bench which also had some sawdust on it. Of course the powder was mixed with the wood. I vaccummed up the whole place and probably had 200gr of pounder in my mini vac. I bet if a primer went off at that point my vacuum would be toast. I cleaned it out right away so never found out , maybe thats what happened.