APPLETON, Wis. - It's become a common reaction across America.
"Unfortunately this is a terrible tragedy," local psychologist Frank Cummings said.
Understanding why these school shootings are happening is something few people can explain.
"This is a tragedy that probably could have been prevented if the warning signs were heeded," Cummings said.
Cummings said the warning signs in this case are not unique. He said there are generally mental health issues and disruptive behavior involved.
"One is that there's an intense anger in the person that they're trying to express," Cummings said. "The second thing is that they feel powerless, so that this gives them a sense of power, and i think the third thing is that they generally tend to be loners."
Cummings said many of those warning signs can be used to try to prevent this from happening in the future.
"I think the major issue here is connecting the dots in advance, and just like law enforcement said, if you see something, say something," he said.
Cumming said in this case that it looks like some warning signs were missed. He said an event like the Florida attack shows that they can't be dismissed.