When the juniors and seniors filed into Hesperia High School's stadium Thursday morning, they were chattering and laughing, like any high school students getting out of class.


Ten minutes later, they were dead silent.


The plastic tarps draped over several large objects on the school's track had been swept aside to show a head-on collision of a truck and car, both spattered with red and senior R.J. Plummley slumped across the hood of his car after apparently having been thrown through the windshield.


It was the school's first "Every 15 Minutes" assembly, meant to bring home the realities of drunk driving, which experts say claim a life in the United States on an average of every 15 minutes.


"R.J. Plummley and James Manibusan chose to celebrate their recent graduation from Hesperia High School by drinking beer with friends," an announcer read out over the stadium loudspeakers. "R.J. knew he was too drunk to drive but James insisted he was OK and took the keys from R.J., even though he himself has drank numerous beers as well. Without warning, James swerved the vehicle into oncoming traffic and hit another vehicle head on. James is awake and trying to make sense of what just took place."


Emergency personnel from the San Bernardino County Sheriff's Department and San Bernardino County Fire Department pulled up and students watched as Manibusan went through a field sobriety test and was ultimately arrested and led off in handcuffs.


The driver of the vehicle struck by Manibusan was identified as Hesperia High teacher Kristie Jackson, whom firefighters strapped to a backboard. An American Medical Response helicopter landed on the football field and Jackson was loaded inside and flown away as Plummley, who never regained consciousness, was taken away in an ambulance.


"Both individuals are struggling to stay alive," the announcer explained. "It is unknown whether either will survive the horrific accident. Law enforcement now attempts to contact the families of both R.J. and Mrs. Jackson so they may be with their loved ones at the hospital."


Students were sent back to class, but the lesson continued the rest of the day: Every 15 minutes, a bell rang at Hesperia High School, symbolizing how often an American dies on average from a drunk driving accident. Each time, another student was called out of class, their absence an analog to their deaths.


The "Every 15 Minutes" program, which has rotated through other Hesperia comprehensive high schools in previous years, is meant to scare students with the dangers of drinking and driving before prom and graduation seasons claim any students' lives.


Based on the chatter on Twitter following Thursday's assembly, it worked on at least some students:


"That assembly made me tear up," Kelsey Leon wrote. "Not cool."


"People who drink and drive are seriously retarded," Aylin Nava wrote. "Hitch a ride, carpool, call a cab, call your mom, walk ..."


"Ever since the assembly I've felt like I'm on the verge of crying," Brittany Goss wrote.


"This bell is starting to get creepy," Arianna Gonzalez wrote, "you start to think about the reality of the situation."


"Every time that bell rings I get a little more sad," Becca Lyons wrote.


Students weren't to learn the fates of Plummley and Jackson until Friday, when a second assembly revealed that both had died as a result of their injuries.