Andrew 'Bart' Simpson, 36, won gold at the 2008 Beijing Olympics and silver in last year's Games in London, both in the Star class.
Born in Chertsey, Surrey, he started sailing at the age of six with his father in Christchurch, Dorset, according to Tyler Sports Management.
Nicknamed Bart, he was awarded an MBE in the 2009 New Year Honours list.
A Foreign Office spokesman said it was aware of reports of the death of a British citizen and had contacted its counterparts in the United States.
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Monica O'Connor and at least two other people were killed in the incident, and a British man remains missing.
Lively downpours across the south, Wales and Northern Ireland today - slow moving and intense with hail and thunder.
"The council's inspector judged there was an imminent health risk and an immediate voluntary closure of the takeaway was agreed."