How can I mention a personal tragedy in a statement for PhD? I am currently applying for my PhD in pure math. I am also finishing up my masters. Unfortunately my brother passed halfway through the semester and I received an incomplete in one of my classes because I was absent too much. I also missed the GRE Mathematics subject test which is required. I spoke to the head of the department who said that they will consider my application without the GRE subject test. I don't know if he is going to personally be reviewing my application or if he's even going to remember he said this to me. 

Anyways, should I put this in my personal statement? So far I've talked only about my math research interests, experience, etc. But maybe I should add a concluding paragraph that explains my current situation? How can I approach this? I took my regular GRE and though my score isn't awful, it's not great and I just feel like my brother passing in the past few months has tremendously had an affect on me. That being said, I've worked so hard and besides this incident, all my grades for my masters degree have been high to low A's. I want them to know this isn't me at my best. But I also don't want it to be a sob story.
Yes, you should absolutely mention it. If you do not, the program will not have the necessary context to evaluate your application fairly -- which is bad for them and worse for you.

You should also mention that the program already agreed to consider your application without the GRE -- as you say, it's anyone's guess whether they will remember this concession if you don't remind them. In fact, I worry that a well-meaning secretary might trash your application in any case (as it appears incomplete), so it might be worth indicating this in a more visible place or even calling to confirm that your application was passed to the committee. 

Now, for how to mention it: concisely. 1-2 sentences is all you need. "I performed poorly during this brief period because my brother died" is all they need to know -- you don't need to dress that statement up too much or say much more than that. 


If you go to town making this statement too long, it will sound like an excuse. So, be very clear, direct, and above all concise.
The one thing that might be worth adding is a reason to be confident that you will not continue to have grief-related problems as a PhD student (i.e., give some evidence that things are improving). 


I do not recommend putting this in the last paragraph as you suggest. The last paragraph should send them off on a high note ("declare victory" and look to the future). Instead, put this into the relevant body paragraph. 

Sorry to hear about your brother.