William Brown was killed last week after his e-cigarette exploded in his mouth outside this Fort Worth, Texas vape shop.

Medical authorities say shrapnel from the pen severed an artery in his neck causing a massive stroke.

He died days later in the hospital, just weeks shy of his birthday.

SOUNDBITE: ALICE BROWN, GRANDMOTHER, SAYING: "Not quite 25-years-old, and he should have had a long life ahead of him." Brown is believed to be the second American to be killed by an exploding e-cigarette.

Last year, a Florida man was killed when his vape pen exploded, lodging pieces of shrapnel in his head.

Vaping devices commonly use lithium-ion batteries which can ignite and explode.

And some e-cigarettes lack safety features to keep the batteries from overheating.

SOUNDBITE: JAY WHITACRE, CARNEGIE MELLON UNIVERSITY ENGINEERING PROFESSOR, SAYING: "Those that are produced by better well-known brands or well-known companies probably use a higher quality batteries probably have a lower frequency of danger." A recent study found that more than 2-thousand people were burned or injured by e-cigarettes between 2015 and 2017.