The deadly Koi Herpes Virus has hit Wolf Lake in northwest Indiana.
According to a report from the North West Indiana Times, the outbreak has been confirmed as being caused by KHV, or cyprinid herpes virus 1 as it is now known.
Dozens of carp are reportedly floating dead on the surface of the Lake and Port Authority staff went out into the east bank of the channel earlier this week and removed around 60 corpses.
At first officials suspected that the fish kill had been due to a chemical or pollution leak, but only carp had been affected - a tell tale sign of KHV.
As in the UK and Europe, KHV is not yet a notifiable disease in the USA. Several outbreaks have occured in the United States over the past year or two.
KHV has been responsible for a number of mass mortalities of fish around the world, most notably including Israel, Japan and South Africa, but the UK has also seen a number of cases reported.