Ethiopian athlete Yebrgual Melese (36) died after falling ill during training, the Ethiopian Athletics Federation announced.
Melese collapsed during training and despite the doctor's quick intervention, she died, reports Gol.dnevnik.hr.
"The Ethiopian Athletics Federation is deeply saddened by the sudden death of this heroic athlete and expresses its condolences to her family, friends and fans," it said in a statement.
Melese won marathons in Prague, Houston, Shanghai and Seoul, and she achieved one of her greatest successes in 2015, when she came second in the prestigious Chicago Marathon.
Her last competitive appearance was the Beijing Marathon, which she failed to finish, in May of last year. At the time of her death, Melese was preparing for the Ottawa Marathon, which was scheduled to take place on May 24.