After weeks of investigation, officials at the Pinellas-Pasco Medical Examiner's Office determined that the cause of the May 5 death was a "projectile wound of the head" and was an accident, the Tampa Bay Times reported. The report also states that D'Elia suffered severe burns on roughly 80 percent of his body.
It's still unclear what caused the device to explode.
When emergency responders first came upon D'Elia's St. Petersburg home, the report indicates they found "extensive" fire damage and minimal smoke in the room where the body was found.
The Federal Emergency Management Agency has since determined that this is the first e-cigarette death in the United States, ABC Action News reported. A separate report from the agency states that when vape pen explosions do occur, the shape of the inhaling devices creates "flaming rockets."
In January 2017, an Idaho man lost seven teeth and suffered second-degrees burn after a vape pen exploded in his face. Before then, a New Yorker suffered third-degree burns after the device exploded in his pants, the Times reported.