Sent Home From Work For Opened Beer Can In My Bag.

I work in a school that has an "Evolv" system, which is a metal detector for guns. My bag went, "off," and I opened my bag for the princial to check when I unzipped my bag I had an empty beer can inside. I was floored, as I knew it wasn't mine. I explained I would take to trash outside. This was first thing in the morning before I went to my classroom. When I called my husband, he informed me he had put the empty can in there from the yard yesterday when he was cleaning up yard. (My bag was in gargae that holds my computer, and he knew I would take it inside. However; I did not take it inside. I had to write a statement and in my statement I explained that I would take a breathalyzer test, lie detector, or whatever was needed. I was sent home and waiting to hear from HR.Can I be fired for this? I am devastated and this is in S.C.