Yesterday, a gunman opened fire on Seattle Pacific University, killing one and injuring four—perhaps more if not for a student named Jon Meis who apprehended the killer.

While one death is even too much, it’s important to look back on just how many people in the United States are dying from gun violence. A data visualization firm called Periscopic compiled all the gun deaths from 2013 in the United States, and made this overwhelming interactive chart, in which all the casualities are tracked in blooming data points that show the age of the victims as well as their potential lifespans had they not been killed. Take a look for yourself.