It hasn’t even been a year since six people were gunned down at Accent Signage in Minneapolis. But since then, six more mass shootings have occurred across the United States, with Monday’s tragedy at the Washington, D.C., Navy Yard being the latest bloody outbreak in an epidemic of gun violence that shows no sign of abating.

Our hearts grieve for the families of the victims of this latest slaying. Twelve people were killed in or near a building housing the Naval Sea Systems headquarters on the Anacostia River — about half a mile from the U.S. Capitol. The alleged gunman, a former Naval Reservist working as a contract employee, also died in the rampage.

But with the grief on Monday came an alarming sense of futility and even fatalism. Mass shootings, while horrifying, are increasingly a routine part of American life. Since Accent Signage, 54 people, including the 20 children killed at the school shooting in Newtown, Conn., have died in such events.

If the young lives lost in Newtown last December couldn’t push Congress or even state legislatures like Minnesota’s to pass tighter gun control measures, what will?

We must be on collective guard in the days ahead, however, to not surrender our outrage over these continued tragedies. A healthy society does not get used to crimes like this. Nor does it shrug its shoulders instead of demanding to know why gunmen like the two who killed at the Navy Yard and at Accent Signage, both of whom had exhibited signs of mental illness, had such easy access to guns.

A “nothing can be done” mind-set does nothing but ensure that another mass shooting will happen. At these crimes’ current rate, look for the next disturbing headlines in about two months.