Joplin, Missouri (CNN) -- Calling the students an inspiration "to me (and) the world," President Barack Obama urged Joplin High School graduates Monday to heed the lessons they've learned and spirit they've shown to rebuild not only their tornado-ravaged Missouri city, but also their nation.
"America will only succeed if we all pitch in and pull together -- and I'm counting on you to be leaders of that effort," said Obama, according to his prepared remarks. "Because you are from Joplin. And you've already defied the odds."
Minutes after 450 seniors from the same Missouri school got their diplomas last May 22, a monster twister tore through the community. More than 161 people were killed -- the worst death toll for such a tornado since modern record-keeping began in 1950 -- while dozens of buildings were torn to shreds.
One of them was Joplin High School itself, with the damage so severe that students ended up attending classes in a vacant section of the city's Northpark Mall.
Obama alluded to students' unique struggles during his commencement address Monday, which was held on the campus of Missouri Southern State University. He referred, too, to broader challenges facing they their townsfolk to work together, dream big and remain positive in adopting their new slogan of "Remember. Rejoice. Rebuild."
"We can define our lives not by what happens to us, but by how we respond," said the president. "We can choose to carry on, and make a difference in the world. And in doing so, we can make true what's written in scripture: that 'tribulation produces perseverance, and perseverance (produces) character, and character, hope.'"
The story of Joplin also showed there are "so many good people in this world," something that he insisted the students never forget.
It was during his remarks about community and unity that Obama shifted from discussing Joplin more exclusively, to talking about the nation in general.
"We need each other. We're important to each other. We're stronger together than we are on our own," he said. "It is this spirit that's allowing all of you to rebuild this city. It's the same spirit we need right now to help rebuild America."
The Joplin High graduates are particularly qualified to do so, according to Obama. They have walked the walk -- by pitching in to assist their neighbors, pursuing their education despite the chaos around them and learning from other city citizens and total strangers about what people can do, against the odds, when they work together.
"Some of life's strongest bonds are the ones we forge when everything around us seems broken," the president said. "And even though I expect some of you will ultimately end up leaving Joplin, I'm convinced that Joplin will never leave you."