"It wasn't a vehicle crash that took his life".

A 16-year-old SC boy who collapsed in a classroom at school and died last month had so much caffeine in two hours that it killed him, a medical examiner said Monday.

Richland County Coroner Gary Watts said Monday in a news conference that the cause of death was a cardiac-event from an excessive amount of caffeine, WYFF reported. During an arrhythmia, or abnormal heart rhythm, the heart may not be able to pump enough blood to the body, and lack of blood flow affects the brain, heart and other organs.

16-year-old Davis Allen Cripe collapsed in a classroom in his high school outside Columbia, South Carolina last month, and died in an emergency room.

Among those at the news conference Monday was the teen's father, Sean Cripe. But it wasn't a auto crash that took his life.

"I stand before you both as a broken-hearted father and hope that something good can come from this", said Sean Cripe, Davis' father.

An initial autopsy done on the boy did could not reveal the cause of death.

Watts did not specify which energy drinks were consumed, but in general, a 24-ounce energy drink can contain as much as 500 milligrams of caffeine.

Davis had purchased the latte at a McDonald's around 12:30 p.m. April 26, Watts said.

In addition to being healthy, Davis was known among friends and classmates for advocating against using drugs and alcohol, Watts said.

"This was not an overdose".

Watts said the boy was doing something he thought was totally harmless, but an excessive amount of caffeine can be extremely risky.

"These drinks can be very risky", Watts said. He added that Davis had "a previous history of drinking" caffeinated beverages but nothing that his family considered to be an addiction.

Dying from too much caffeine is "very rare", said Cherokee County Coroner Dennis Fowler, president of the S.C. Coroner's Association.

While McDonald's doesn't now report the amount of caffeine in their coffee, Caffeine Informer estimated a large, 21-24-ounce McDonald's latte contains 178 milligrams of caffeine.

For a healthy adult that can consume up to 400 mg of caffeine per day, exactly how many energy drinks, sodas or Cafe Lattes would put them over the edge? "Parents, please talk to your kids about these energy drinks".

He also urged people to avoid highly caffeinated drinks.