There are not enough facts for me to answer this question. Generally speaking, there are only a few ways to prove that race was a factor in a termination decision. The most direct way is to show that the persons that were involved in the termination decision were making negative comments about your race. Another way is to show statistically that there is a pattern of racial inequality. To prove it statistically you would need a large enough sample pool and some knowledge of the races of people who have applied for jobs with the employer along with their qualifications as well as the races and qualifications of people who have been laid off or terminated. The fact that they only employ one black person and then terminated that person sounds suspicious but it would be less so if the store only had five employees, or if there were very few qualified black people applying for positions.