A 16-year-old South Carolina boy consumed a large Diet Mountain Dew, a cafe latte from McDonald’s, and an energy drink within the course of 2 hours, and it evidently cost him his life. 
Davis Allen Cripe’s caffeine splurge likely caused deadly a heart arrhythmia, according to Richland County coroner Gary Watts.
“It was too much caffeine at the time of his death that it caused his arrhythmia.”
The Mayo Clinic explains heart arrhythmias this way:
“Heart rhythm problems (heart arrhythmias) occur when the electrical impulses that coordinate your heartbeats don’t work properly, causing your heart to beat too fast, too slow or irregularly.
Heart arrhythmias (uh-RITH-me-uhs) may feel like a fluttering or racing heart and may be harmless. However, some heart arrhythmias may cause bothersome — sometimes even life-threatening — signs and symptoms.”
It was around 12:30 p.m. on April 26 when Davis purchased the latte at McDonald’s. The Diet Mountain Dew was consumed “a little time after that.” Then, the young man consumed the energy drink, which officials declined to identify. 
EMT’s were called at 2:28 p.m., when Davis collapsed. He was pronounced dead at 3:40 p.m., at Palmetto Health Baptist Parkridge Hospital.
In April 2017, a study was published in the Journal of the American Heart Association linking energy drinks to heart problems. Caffeine isn’t the only potentially hazardous ingredient in energy drinks, however; the beverages contain numerous ingredients which, on their own, may not be hazardous, but create a potent cocktail when mixed with caffeine.
In the study, participants who drank a regular caffeinated beverage showed no signs of abnormal heart rhythms. But after they consumed an energy drink, some of the individuals’ ECGs showed a change called QTc prolongation that is sometimes associated with life-threatening irregularities.
“These drinks can be very dangerous. I’m telling my friends and family don’t drink them.” 
In the case of Davis Allen Cripe, though, it appears that caffeine was the main culprit. The official cause of death was a “caffeine-induced cardiac event causing a probable arrhythmia.” Still, Watt stopped short of calling the boy’s death a caffeine overdose. 
The coroner said Davis was a healthy teenager, with no family history of a medical problem the caffeine would have exacerbated. The teen’s friends said he was staunchly against drug and alcohol use.
“Davis, like so many other kids and so many other people out there today, was doing something (he) thought was totally harmless, and that was ingesting lots of caffeine. We lost Davis from a totally legal substance.”
Dr. Amy Durso, deputy chief medical examiner for Richland County, said:
“A cup of coffee, a can of soda isn’t going to cause this thing. It’s the amount and also the time frame in which these caffeinated beverages are consumed that can put you at risk.”
Plus, caffeine and energy drinks affect people differently. Your buddy might be able to knock back 2 energy drinks and a cup of coffee in the morning with no ill effects, but you shouldn’t assume it’s safe for you, Watts said.
“You can have five people line up right here and all of them do the exact same thing that happened with him that day – drink more – and it may not have any kind of effect on them at all.”
Sean Cripe said of his son’s death:
“Like all parents, we worry about our kids as they grow up. We worry about their safety, their health, especially once they start driving. But it wasn’t a car crash that took his life. Instead, it was an energy drink.” 
“Parents, please talk to your kids about these energy drinks. And teenagers and students: please stop buying them.” 
 NBC News
 Miami Herald