This happened to me (severe personal/family issues took place), and throw in an incomplete into the mix...I almost dropped out and took a PELP due to the burden...
At the time of application, the Incomplete was on my transcript. But I did make the class up, and the adcom did ask about that. They were very understanding, and I didn't have to explain too much. I have had great success this application cycle (will be attending my IS UC Davis), despite my GPA suffering greatly (it dropped a whole .5, maybe more, within 2 quarters), and once it drops it is extremely difficult to bring back up. I can tell you more about it over PMs if you would like. Best of luck!