On 30 August 1946, the legendary test pilot Jack Woolams, known all over the world for his records and peculiar “aviation” humour, died in an accident in the United States at the age of 29. It happened during a training flight before the National Air Races in Cleveland, Ohio, which were due to take place the following day.

Woolams was testing the “Cobra I” aircraft over Lake Ontario late in the afternoon at speeds of over 400 miles per hour. Suddenly and inexplicably he crash-landed into the water. His body was discovered four days later. After the wreckage was found, experts agreed that damage to the cockpit canopy caused the crash.

Woolams was the holder of numerous records and achievements and was regarded as one of the world’s best test-pilots. He was famous for playing jokes on other pilots, for example, he once joined a formation of old military aircraft while flying a new high-speed aircraft while wearing a gorilla mask with a cigar between his teeth.
His death was one of many during the shift from piston to jet propulsion aircraft engines. In the USSR, the legendary test pilots Viktor Masich, Yakov Bogdanov, as well as the world`s first cosmonaut, died while testing jets. 

Source:

Sterling Michael Pavelec (2007). The Jet Race and the Second World War. Greenwood Publishing Group