Divers were searching for three other possible victims that were missing while seven people were taken to hospital following the incident on the “Ride the Ducks” amphibious vehicle on Table Rock Lake, near Branson, Missour.
Emergency crews responded to the incident shortly after 7pm after thunderstorms rolled through the area, the fire district said on Twitter.
A spokeswoman for the Cox Medical Centre Branson said four adults and three children arrived at the hospital shortly after the incident. Two adults were in critical condition and the others were treated for minor injuries, Brandei Clifton said.
National Weather Service meteorologist Steve Linderberg said a top wind speed of 63 mph was measured around 7pm Thursday at Branson Airport. The winds were likely stronger over the lake, Linderberg said.
Multiple dive teams from a number of law enforcement agencies were assisting in the rescue and recovery effort. Mr Rader said the divers ended their search for the night.