The 74 school shootings since Sandy Hook

For Americans, the scene was mind-numbingly familiar.

SWAT teams with guns drawn, descending on a campus after reports of gunfire. Students streaming out of buildings with hands raised in the air. Crying parents frantically trying to reach their children. Media swarming. Helicopters hovering overhead. Communities shaken.

Young lives lost.

Tuesday's deadly shooting at Reynolds High School in Troutdale, Ore., was the 74th school shooting since the Dec. 14, 2012, massacre at Sandy Hook Elementary School in Newtown, Conn., according to Everytown, the grassroots gun control group launched earlier this year by former New York City Mayor Michael Bloomberg. (Everytown defines school shootings as incidents in which "a firearm was discharged inside a school building or on school or campus grounds" and includes "assaults, homicides, suicides, and accidental shootings.")

Put another way, there has been, on average, a school shooting every 7.35 days since the tragedy in Newtown — a statistic not lost on President Barack Obama.

"We're the only developed country on Earth where this happens," Obama said Tuesday during a question-and-answer session on Tumblr. "And it happens now once a week. And it's a one-day story. There's no place else like this."

While gun rights advocates say that failings in the country's mental health system are to blame for the seemingly endless string of U.S. school shootings, Obama said the nation must figure out a way to keep guns out of the hands of the mentally unstable.

"The United States does not have a monopoly on crazy people," he said. "And yet we kill each other in these mass shootings at rates that are exponentially higher than anyplace else. Well, what's the difference? The difference is these guys can stack up a bunch of ammunition in their houses, and that's sort of par for the course.

"The country has to do some soul searching about this," Obama added. "This is becoming the norm."

A map of the school shootings since Sandy Hook, posted to Twitter by Huffington Post editor Mark Gongloff, has been retweeted more than 1,000 times.

In response to the shootings in Newtown, Obama and Vice President Joe Biden made a big push to reform the nation's gun laws, championing legislation that would have expanded background checks and placed a ban on some military-style assault weapons and high-capacity gun magazines. But the effort was defeated in the Senate.

On Tuesday, Obama said lawmakers should be "ashamed" for not taking action to reform U.S. gun laws, especially in the wake of the Sandy Hook killings.

"I have been in Washington for a while now. Most things don't surprise me," Obama said. "The fact that 20 [children] were gunned down in the most violent fashion possible and this town couldn't do anything about it was stunning to me.

"Right now, it's not even possible to get even the mildest restrictions through Congress," he added. "And we should be ashamed of that."

Everytown is hoping to do what Obama has not: successfully lobby for stricter gun control laws.

"Communities all over the country live in fear of gun violence," the group said in a statement after Tuesday's school shooting. "That’s unacceptable. We should feel secure in sending our children to school — comforted by the knowledge that they’re safe."