On this day last year, after the worst tragedy I could imagine happened in my very own city, I issued a plea to donate blood. Unfortunately, much of the blood donated over the next week went unused, and had to be thrown away. Now, a year later, the U.S. blood supply has reached a critical low, something I can personally verify with the stories of my two patients who had to wait for special deliveries from the area blood bank in order to get their much-needed transfusions.

If you can find it in you to spare half an hour sometime over the next week or two, please, go give blood. You’re providing life, which seems to me to be a terrific way to pay respects to those whose lives were lost last year.