"Christina Kamser, who participated in a rain marathon organised by Rotary Club of Panaji, collapsed soon after she started the 10-km run," Assagaim Police Inspector Uday Parab told PTI.
She was immediately rushed to Goa Medical College and Hospital near here, where she was declared "brought dead."
Parab said the cause behind Kamser's death will be known after postmortem report arrives.
"We have also called the girl who accompanied the deceased to the run. We are inquiring the case," the officer said, adding that Agassaim police have registered a case of unnatural death.