And now it's Roseburg, Oregon.

Another peaceful community has been shattered by inexplicable violence and the chilling words "active shooter." More stunned residents watched in disbelief as emergency vehicles screamed down their streets. Another set of students was hurried out of classrooms with hands on or above their heads.

It's our national nightmare, and we can't -- or won't -- wake up. The horror unfolded Thursday at Umpqua Community College, where at least 10 people, including the shooter, were killed and as many as seven were injured. There have been dozens of shootings on school campuses since the Sandy Hook massacre traumatized the nation less than three years ago. However, that bloodshed failed to result in any meaningful federal gun laws.

We can complain -- rightly -- that our country is awash with guns. We can complain -- rightly -- that we must take mental health issues more seriously and get counseling to those who need it. We can complain -- rightly -- that each of us has to say something if we hear or see something. The suspected shooter, Chris Harper Mercer, 26, might have discussed his plans in an online chat room the night before the shooting, warning others not to go to school on Thursday, and was greeted with encouragement and advice on how to pull it off. But complaints are not enough.

President Barack Obama, shaken and frustrated as he addressed the nation, made a full-throated cry for commonsense gun-control legislation. "We collectively are answerable to those families who lose their loved ones because of our inaction," he said, and demanded a collective response. That's the right call. He challenged Congress, state legislators and governors to join him, saying he cannot do this alone. And, knowing the majority of Americans want stronger gun laws, he asked voters to elect people who reflect their views. Think about how we can get government to change our laws, he said, to "save lives and let our young people grow up."

It was a powerful and poignant response to another unbearable tragedy. Unfortunately, it was the 16th time Obama has had to do that.