ST. PETERSBURG, Fla. – An autopsy confirmed that a St. Petersburg man found dead earlier this month was killed after his vape pen exploded, burning more than 80 percent of his body.

Medical examiner also found that two pieces of the vape pen became projectiles when the device exploded near 38-year-old Tallmadge D'elia on May 5. The mouthpiece of the pen was found lodged in his brain, the autopsy found.

Vape pens are electronic cigarettes that produce vapor that users inhale. They are battery-powered and simulate the feeling of smoking, but without burning tobacco.

Explosions involving vape pens are uncommon, but faulty devices have been the subject of a handful of media reports in recent years. Last year, a vape pen exploded in an Idaho man's face, causing him to loose seven teeth. The explosion was so powerful that it shattered the man's bathroom sink.

Experts say that people who use vape pens should be careful about how they maintain the batteries.

The Food and Drug Administration recommends that smokers should not leave pens charging overnight or use off-brand chargers.