The gruesome images will be tough to erase for the hundreds of kids who poured out of Harry S. Truman High School in Levittown on Thursday.

Three wrecked cars right in front of their Bucks County school. The anguished screams of "Somebody please help!" The grisly sight of wounded classmates like 17-year-old Marlee Jardine drenched in blood. The sounds of police sirens and the thumping blades of a medical chopper. Finally, watching a silver hearse arrive.

"I grew up with these people," said Olivia Burgo, 17, while a local rescue squad used the Jaws of Life to pull her friends from the wrecked cars on the sunny and hot morning. "It's hard to see them like this. My stomach hurts." Other students looked just as stunned.

School officials certainly hope Truman's seniors won't forget the trauma. Holding onto those feelings of shock and nausea is the main idea behind the annual mock car crash at the 1,500-student Bristol Township School District high school, one of many similar fake-blood-spattered events staged this prom season around the Philadelphia region, aimed at scaring teenagers away from drunken or, increasingly, distracted driving.

It's fitting that one of the most dramatic of these events takes place at Truman – the "Drama High" whose award-winning theater program inspired the hit NBC show Rise! Painful lessons are driven home through an elaborate daylong program in which – in addition to the gruesome wreck — a hulking classmate dressed as the Grim Reaper yanks students from classrooms as the remaining kids hear fake obituaries written by the kids' parents, most composed over real tears.

"We have had kids show up years later saying, 'We never forgot. We talk about it all the time,'" said Jill Saul, a special education teacher who's directed the annual mock crash – which costs about $4,000 to stage – for much of its 20-year history. Over that time, the rites – from buying cheap "prom dresses" at a thrift store to selecting popular kids to play the dead and the dying – have become as much a part of May as the prom itself. The formal will be held May 18 at the Radisson Hotel in Trevose.

Chazen Murray portrays a passenger ejected from the backseat onto the hood of the car during the mock crash at Truman High School.
Kathy Boccella
Chazen Murray portrays a passenger ejected from the backseat onto the hood of the car during the mock crash at Truman High School.

But amid the screams and sirens, there's an increasingly loud debate among the drunken-driving-prevention community about whether the core premise of the phony crashes – that seeing the carnage and experiencing pangs of grief will frighten teenagers into avoiding alcohol or arranging safe rides – actually works.

Some advocacy groups, including Students Against Destructive Decisions (SADD), have come out against mock crashes as a prevention tool, citing research showing that their psychological impact on teenagers' decision-making may fade as soon as summer, the deadliest season for teen auto fatalities.

SADD and Mothers Against Drunk Driving (MADD) have called for comprehensive ongoing programs to combat drunken and distracted driving, as opposed to the shock value of a one-time event. Critics also worry that the morbid mock crashes will do psychological damage to some teenagers, outweighing any driving-safety benefits.

"From a public health perspective, we have learned that shock and awe methods of prevention do not lead to long-term change," said Kim Everett, trauma prevention coordinator for St. Mary Medical Center in Langhorne. The Bucks County health center used to donate $500 or $1,000 every year to defray the cost of Truman's production, but stopped two years ago, about the time that the Pennsylvania Department of Transportation said state funds shouldn't go for such events but rather for evidence-based programs, according to Everett.

Still, the popularity of mock crashes grew during a period when teen traffic deaths plunged sharply – by more than half from 2005 to 2014, according to the Governors Highway Safety Association. But the Washington group then saw a 10 percent spike in 2015 that experts link to a rise in teen drivers distracted by texting or other devices, and car crashes remain the No. 1 cause of teen death. Advocates say more focus is needed not just on distracted driving but a lack of teen awareness that driving while high on marijuana is also dangerous.

Any caution flags from advocates and highway-safety experts don't seem to have slowed the growth of mock crashes at Philadelphia suburban high schools. Two years ago, Main Line Health heralded a $45,000 grant from State Farm Insurance to expand its program to include 11 high schools in the western suburbs, including Penncrest, Ridley, Garnet Valley, and Villa Maria Academy.

Teacher Jill Saul comforts an emotional Melissa Centeno, who portrays a distracted driver, during the mock car crash at Truman High School.
Kathy Boccella
Teacher Jill Saul comforts an emotional Melissa Centeno, who portrays a distracted driver, during the mock car crash at Truman High School.

"I think it's really trying to have the kids stop and think about the consequences," said Main Line Health's Deborah Mantegna, manager of community health services. Its program also includes a speaker who warns about the consequences of drunken driving — not just injuries and death, but the financial costs and how a DUI arrest might thwart college admission.

"Our feeling is, if it saves one kid, then it's effective for us," said Carole Roskoph, activities coordinator and English teacher at Cherry Hill High School West, where kids – along with those from crosstown Cherry Hill East – have been staging mock crashes for about 15 years with help from township police.

Saul said there has not been a drunken-driving death among their students for many years. (A couple of years ago, a Truman student who participated in the mock crash died a few months later in a drag-racing incident that didn't involve drinking.)

Over the years, the event has been expanded or tweaked. "Injured" or "dying" kids are actually taken to hospitals, by ambulance or helicopter, and police arrest the "drunk" driver, who goes before a judge, then to jail.

Every year, after the trauma of acting out their own deaths, the victims and other participants retreat after school to a local hotel to relax and decompress, before enduring another emotionally grueling experience: hearing speeches from family members affected by drunken-driving crashes. The students stay the night and the next day share what they've learned from the experience with their classmates at an assembly.

"Most kids are receptive to it," said Truman principal Lyndell Davis, a strong proponent. "Some kids, like most teenagers, think they're invincible."

Shakira Alford – whose 17-year-old daughter, Brianna Cliney, was tapped by the Grim Reaper to become a "ghost" in the Truman exercise – said she recently lost a nephew in a car crash. Although she called it "a little scary" to write a tribute as if her daughter had died, Alford said she came around to support an event that "will be an eye-opener when it comes to getting in a car."

On the morning of the fake crash Thursday, Truman kids were whipsawed between the theatricality of the event and its grim message. "I think we're laughing it off to hide the fact that we're shook," said Manilyn Lalo, 17, while getting made up with wounds and gashes to become a victim in the "sober car" walloped by a drunk driver.

Even if the blood was fake, the emotions were undeniably real.

"I want you to know how much I love you," Saul said, tearing up as she addressed students after the "victims" had left for the hospital where traumatized parents would get the news that their child had died, and the hearse slowly drove away with the body of a student who had been killed at the scene. "I don't want to ever go to your funeral. Please make good choices and healthy choices."