William Brown, from Fort Worth, Texas, was using the vape while in his vehicle outside the Smoke and Vape DZ store last month, just moments after buying the device, says his grandmother.
She continued: "It just all seems so unreal".
"That three-piece thing went into his throat and stayed there", Ms Brown told KTVT. A passerby called an ambulance and he was taken to hospital, where he died two days later.
The death certificate says he died from cerebral infarction and herniation after debris from the exploding vape pen dissected his left carotid artery.More news: Marshmello’s concert in Fortnite was absolutely bonkers
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The explosion happened in the parking lot of a Fort Worth vape shop on January 27.
William Brown is at least the second person in the United States reportedly killed by an exploding e-cigarette.
A report from the US Federal Emergency Management Agency said 133 people were injured by faulty devices between January 2009 and December 2016. When he went back to his auto to use the vape pen the battery exploded, she said.
William Eric Brown "had a future ahead of him; a life ahead of him", Alice Brown remarked to the station about her grandson. Furthermore, Alice told the Star-Telegram that she did manage to find the pen's battery, which still had the serial number, when searching her vehicle. The agency notes that most explosions occur while the device's battery is charging. She had to go through it to find the pieces of the destroyed vape pen and said she managed to find the key piece - the battery showing the serial number.
In May, Florida authorities investigated the death of a 38-year-old man named Tallmadge D'Elia, who suffered multiple injuries to his face. He was said to have suffered burns over 80% of his body.
Vape pens and e-cigarettes typically come with a battery and heating element and can resemble regular cigarettes, cigars or pipes, while others resemble pens or USB sticks. The Centers for Disease Control and Prevention (CDC) warns that the devices can cause unintended injuries, especially if the product is defective. A piece of the e-cigarette was found in his throat and he was put into a medically-induced coma. The Star reported that a Texan man was killed when his vape exploded in his face.