The Indiana mother who mysteriously fell ill on an American Airlines flight returning from the Dominican Republic suffered from a carotid artery dissection, her brother revealed Wednesday.

Stefanie Smith, 41, became sick on February 28, while she and her boyfriend were traveling back to the United States after a five-day Caribbean vacation. The flight was diverted to Turks and Caicos, where Smith was pronounced dead in the hospital, according to ABC News.

Two weeks after the mother-of-two became fatally ill, her family has finally received confirmation that she died of natural causes.

"It was truly a tragic medical event that happened," her brother Chris Volz told ABC News.

Smith's body was examined by a forensic pathologist, who ruled out any foul play. The death was surprising to loved ones, who said that she was healthy and went for a run every morning while on vacation, ABC News reported.

"Her endless love for her family, friends, and community will leave a lasting impact on all who had the privilege of knowing her," a GoFundMe created for her teenage children read.