Still can’t find any credible reports of this happening to an UN-Vaccinated 18 year old.
Lots and lots here, long before there was any Covid or Covid vaccine:
Sudden Deaths in Young Competitive Athletes: Analysis of 1866 Deaths in the United States, 1980–2006
https://www.ahajournals.org/doi/10.1161/circulationaha.108.804617
it happened due to heat exhaustion or undetected heart conditions well before for the vaxx came along and made matters worse.
EasySt wrote: “Still can’t find any credible reports of this happening to an UN-Vaccinated 18 year old”
Perhaps you should do some research instead of relying upon anti-vaxxine conspiracy theories.