Can an employer be held responsible?

I worked in a job,a very physically demanding job,for 10 years.I worked days and there was another employee in the same job as me on second shift.For the three years he was employed there Im guessing of 100% of the total work done 95% was done by me . Fellow employees would attest,as it was a running joke in our company for 3 years.3 years ago I was diagnosed with some very serious medical problems and 2 years ago I had surgery which was supposed to significantly limit my duties at work according to restrictions placed on me.My restrictions were broken daily,which I relize I was partly responsible for,and Im not afraid to say that my workload if anything increased instead of decreasing.While in turn my counterparts on 2nd shift decreased.Basically I was doing 99% of the work while he mostly slept at night or was never even there..My foreman informed me at least 15 times of how this employee was going to be fired for not doing his job and for even stealing from the company.In November,over the Thanksgiving weekend,I had worked feverishly to keep my jobsite afloat working all four days while other employees were off and our job was shut down.My counterpart also"worked" these four days and it was known by my foreman that he done absolutlely nothing the whole time he was there.The following Monday I had a near death experience as ,according to my Dr.,the over exertion from the previous 4 days had caused me to pass out,falling face first in 8" of water.A fellow employee saw it happen and pulled me out..After four days in the hospital I was informed by my employer that they no longer had anything for me at my jobsite to accomodate my restrictions.Im going to give you 1 guess at who has my job now..Yes your right my counterpart from second shift.With everyone I worked with in the entire company knowing that I was being "worked like a dog" and this guy was "getting away with murder" do I have any recourse against anyone be it the company,the foreman or the employee for me no longer having a job.I mean is it fair or is there a law against working one guy to death and then replacing him with the reason he was worked to death..