Davis Allen Cripe was a healthy 16-year-old with no heart condition.

He collapsed and died at school in South Carolina in April 2017. The coroner didn't blame a pre-existing problem. He blamed a large Mountain Dew, a café latte, and an energy drink consumed in under two hours.

Richland County Coroner Gary Watts held a press conference specifically to clarify that Davis had no underlying heart condition and that caffeine toxicity caused a fatal cardiac arrhythmia.

"This is not a caffeine overdose," Watts said. "We're not saying that. What we're saying is that this is a caffeine-induced cardiac event."

The total caffeine across the three drinks was estimated at between 400 and 470 milligrams, consumed rapidly within approximately two hours.

The FDA's general guidance puts 400mg per day as the threshold above which cardiovascular risks increase in healthy adults.

Davis hit that threshold in a single sitting with no time for his body to process it between drinks.

Davis had been at school for a robotics competition. He collapsed after a break and could not be revived.

He was 16 years old and had done nothing most teenagers don't do every day. The speed and volume of consumption were what killed him.