Joplin, Missouri (CNN) -- Like nearly every high school senior who has donned a cap and gown, Scott Lauridsen was excited.
Finally, after four years at Joplin High School, it was time to go. Graduate. Celebrate. Step up to the next stage of his young life.
"I was excited -- ready to start things new and move onto college and experience life and then all this happened," said Lauridsen, 18, one day after one of the deadliest American twisters on record ripped through his hometown of Joplin, Missouri.
"Now I'm just worried about helping out with the community and getting things back together," he said.
A recent graduate's joy: Another casualty of Sunday's terrible tornado.
Lauridsen was one of about 450 seniors to receive a diploma from Joplin High School this year. Their graduation ceremony at a local university wrapped up just as the storm started to roll in.
Students streamed out of the gymnasium and onto an open lawn as proud parents, family and friends snapped pictures -- smiling graduates against a backdrop of darkening skies. A light rain began to fall and people rushed to their cars.
Aaron Frost, another graduate, left with his girlfriend. They were headed to a restaurant to meet his family when Frost, 18, got a call from his mother.
"She pretty much demanded that we pulled over," he said. "I would have drove right into the storm. My mom pretty much saved me there."
Frost and his girlfriend ducked into a Fast Trip convenience store and took cover, along with about 18 other people, inside a walk-in cooler.
"You can't really do anything," he said. "We just bent over and covered our heads."
A piece of glass struck Frost's hand but otherwise he is fine. The store and his car were not as lucky.
Later, Frost went by his old school, where the roof was ripped off and debris was strewn across the lawn.
Kerry Sachetta, principal at Joplin High School, described the damage as "terrible."
"I walked around as much as I could to see it and it just looks like it's been bombed from the outside in," he said.
Joplin's public school district has canceled classes for the rest of the year.
"To see my high school flattened is especially hard," said Frost. "It's indescribable."
His concern is made worse by the uncertainty of not knowing what happened to some people from his community. Phone service in the area is spotty and friends have struggled to connect.
Lauridsen said Will Norton, another Joplin graduate and a friend of his, is missing. Norton and his dad were driving home when the storm hit. A Facebook page has been set up to help locate him.
"My dad said ... his seat belt snapped and he was ejected through the sunroof," said Sara Norton, Will's sister.
Their father is in stable condition, she said, but the family is still trying to pin down exactly where Will might be.
"It just makes me sad to know so many of my classmates have lost their homes and some of them are still missing," said Taylor Costley, 18, another 2011 graduate of Joplin High School.
She rode out the storm at home with her father, brother and grandparents, fearing for her mother who was briefly -- but terrifyingly-- out of contact.
"Graduation's supposed to be a joyous occasion, but we can't really feel that happy about it," Costly said. "At the same time, I'm so thankful I'm OK and my family's OK."
CNN's Dana Ford contributed to this report.