Miss my exam due to train issues. Help?

I go to college in New York City, but take a train which is like 30 minutes. Unfortunately, today I have an exam and the trains are not operating for another two hours. I emailed my professor and she said that if I miss the exam I will get a zero, but she drops the lowest of three exams. Obviously this is fine, but I really studied for the exam and it is not my fault the trains aren't working. Do you think it is fair that she will give me a zero anyways? Thanks