I had a "bad grade" in a class in my 4th year of undergraduate studies.

The problem is that this class is crucial for the graduate program I intend to pursue. I got a 91%, which I know is a really good grade, but I hoped to get more since I want to do a Master's in Photonics or Electromagnetics. I think that the reason why I got this grade is that one family member passed away a week before my exam and I didn't have the energy or the will to study at that moment.

Do you think that this grade can influence my graduate admission chances?