USA Swimming said it would open its own probe of the death of American open-water swimmer Francis Crippen at a World Cup event in the United Arab Emirates.

“USA Swimming’s investigation will examine exactly what happened to Crippen, why it happened and what can be learned to keep such an incident from happening again,” the American federation said in a statement.

The probe will be independent of the investigation promised by world governing body FINA.

Crippen, 26, died on Saturday during a 10km marathon World Cup in Fujairah. He failed to complete the race and was found in the water two hours later not far from the finish. He was taken to hospital where he was pronounced dead.

On Sunday, Al-Ittihad daily quoted Ibrahim Mohammed, manager of the Fujairah International Marine Club that hosted the event, as saying Crippen’s death “was the result of a heart attack”.

Christine Jennings, a USA competitor who also competed at the UAE World Cup, told the Washington Post that she believed the unusually warm water may have been a contributing factor.

Jennings told the newspaper she vomited several times in the water, became dizzy and veered off course.

Crippen, bronze medallist at the Rome worlds in 2009, had ambitions to become the first American to medal in open water swimming at the 2012 London Olympics.

“What happened in Fujairah is an absolute tragedy, and a thorough investigation must be conducted to provide clear answers to the Crippen family and swimming community, as well as to identify and establish clear guidelines by which all international competitions should be conducted,” said Chuck Wielgus, executive director of USA Swimming.