Their car plunged into a creek near Wilmington, Ill., about sixty miles southwest of Chicago. Questions remain over how the car wound up in a creek.
Wednesday was an especially difficult day for the about 440 students at Wilmington High School are dealing with the unexpected death of their classmates.
"It's sad that something like this can happen so suddenly. I'd seen them all Monday," Wilmington High School junior Tom Catlin said.
Many students were wearing black as they returned to class and came together to mourn.
"You have to go back," Wilmington High School senior Bret Shepard said. "You gotta get through it eventually."
Wilmington residents also gathered for an emotional service at a local church to remember the victims.
Family and friends of the four teenagers have been gathering at the bridge over Forked Creek where the victims were found. They placed crosses, candles and flowers for 14-year-old Matthew Bailey, 15-year-old Micalah Sembach,15-year-old Cody Carter and 17-year-old Cheyenne Fender.
"I'm devastated right now," a friend of the victims John Widner said. "My heart's in my chest right now."
Early Tuesday morning a bus driver spotted one of the wheels of the submerged black Mitsubishi Eclipse while crossing the bridge. A guardrail was also gone as the car had landed upside down in the water.
Divers found the car's windows rolled up and all four teens inside.
Fender, the oldest, was behind the wheel.
Relatives had last heard from the four late Monday afternoon. When they didn't return at curfew that evening and none of the four teens were answering their phones.
"Everybody knows everybody," Sembach's aunt Melissa Robertson said. "A town like this, you know. That's why we had half the neighborhood all night looking for all the kids."
While police investigate exactly what may have caused the car crash, people who live in the small town are coming to grips with the tragedy.
"We've been told by one of the residents that lives near this area that yesterday evening, there was a lot of water, standing water over the roadway," Deputy Chief of the Will County Sheriff's Department Ken Kaupus said.
Although investigators do not know the exact cause of the crash, the accident has sparked conversation about driving safety.
"One of my friends yesterday was saying how they're going to start paying attention on the roads and being careful," Wilmington High School junior Andrew Liaromatis said. "Just can't believe it happened. It's hard."