A young Marine from Rochester has died from a sudden and rare illness.

According to a Facebook post by his mother, Lynda Kiernan, 18-year-old Becket Kiernan of Rochester passed away February 5 from an extremely aggressive bacterial infection known as necrotizing fasciitis.

Becket Kiernan died at 29 Palms Marine Base in Palm Springs, California, where the Old Rochester graduate was fulfilling his lifelong dream of serving in the Marines.

Originally, Kiernan was diagnosed with the flu. His mother tells WPRI-TV that her son passed away only about eight hours after doctors realized he was actually fighting the deadly flesh-eating bacteria.

Doctors are still trying to determine how he came down with the infection.