An employee at the store said Brown never entered the store and declined to comment further.
Local media reports indicate that after the explosion, William was able to get out of the vehicle to search for help; however, he ultimately collapsed near the trunk of the auto. He was just weeks away from his 25th birthday.
William Brown was at a vaporiser store in Keller in the United States when it happened.
Alice Brown said she has no intention of suing the hospital or the company that produced the e-cigarette that caused the tragic accident, because it will not bring her grandson back.
The Tarrant County Medical Examiner's office says shrapnel from the explosion severed his left carotid artery and peppered his skull.
He died at John Peter Smith Hospital two days after crawling from the auto to the trunk area where he collapsed on the pavement, she said. It's a waste of the things he could have accomplished, ' she told the Fort Worth Star-Telegram.
When William got out of the store, he made a decision to use his vape pen in his auto, which is when it combusted.
'It just all seems so unreal.
A mechanical mod is an unregulated style of vaporizer that does not have circuitry to keep the voltage steady throughout the life of the device's battery. "That three-piece thing went into his throat and stayed there", she continued. She said Tarrant County investigators told her the issue is the battery on the device.
"That's the important part", Alice said. The incident adds to a growing number of devastating vape explosions. Tallmadge D'Elia died in May from the incident and suffered burns on 80 percent of his body. None of those injuries resulted in death, according to the report.
A report from the US Federal Emergency Management Agency said 133 people were injured by faulty devices between January 2009 and December 2016.
The moment an e-cigarette exploded into flames in a man's pocket was caught on camera in California previous year.