There is a difference between firing an employee who filed a workers’ comp claim and firing an employee because he or she filed a claim. Your employer is within its rights to terminate your employment after you filed a workers’ comp claim or even while you are receiving benefits.
There is no law requiring your employer to hold your position open while you are unable to work. They have a business to run. If you are no longer able to do the job, or do your job with reasonable accommodations, they may be within their rights to fire you and hire someone else. The Americans with Disabilities Act makes it illegal for your employer to fire you if you can perform the essential functions of your job with reasonable accommodations.
That said, your employer needs to do its part to help you perform the essential functions of your job. This could include installing a device to help you take phone calls because you lost your hearing. It may also be possible to use technology to allow you to do your job with vision loss or visual impairment.
However, it might not be possible to do the essential functions of your job with certain injuries, such as an amputation.
Other reasons your employer could fire you include:
Restructuring of the company
Financial problems at the company that do not relate to your job performance
Poor performance