Do I have a case if I was injured on the job but then terminated two days later?

I was on the phone with my boss when I was leaning against a table that collapsed. I went to Medcor(my employer's medical contact). He said he was not allowed to write a work release, but gave me a letter of restrictions so broad that I could not complete my job duties. I called off for the next days, and found coverage (I am the GM of the restaurant). I received a call Monday when my area manager came back from vacation. He asked why I didn't work and I said I was in too much pain from my injury. He said the letter stipulated I could work and he needed me to work the next day. I said I would, but before that, he asked me to meet him that same day to fill out a statement. I went in before work and they fired me for closing the store early over a week prior. The issue is, I could not get a hold of either boss to get an ok, and I was the only person in the store so I would have been fired for violating a security procedure if I had stayed open.