Ex-CNBC producer killed by his own vape pen: How did it happen?

A former CNBC producer died this month after his vape pen exploded, a Florida medical examiner confirmed this week.

The body of Tallmadge Wakeman D'Elia, 38, was heavily burned when St. Petersburg firefighters entered the upstairs bedroom where he died. It was later determined that the exploding e-cigarette started a blazing fire, and the item itself struck D'Elia to create a "projectile wound" in his skull.

Using an e-cigarette is "like having a small, little larger than a firecracker, in your hand," said Lt. Steven Lawrence, a deputy fire marshal in the area. "It can explode and at that point it can project either the pieces of the lighter itself or the vape pen. They become pieces of flying debris and shrapnel."

While vape pen explosions are uncommon, when they do occur, the items behave like "flaming rockets," according to a recent FEMA report cited by ABC affiliate WFTS.

D'Elia's is the first known death in the United States caused by an e-cigarette.

RELATED: Celebrity deaths of 2018