A teen who was found dead five days before graduation died from a caffeine overdose. According to a coroner’s report, the teen had more than 70 micrograms of caffeine per milliliter of blood compared to three to 15 micrograms found in a typical energy drink. The teen, who apparently ordered the powdered form of the drug online, suffered cardiac arrhythmia and seizures brought on by ingesting the caffeine. According to a USA Today report, a 12 oz. cup of Starbucks coffee contains 260 milligrams of caffeine while a teaspoon of pure caffeine can contain up to 1600 milligrams. Read more: Autopsy finds Keystone senior died from caffeine overdose