[3]: 343  Police discovered him unconscious in his car in Las Vegas on October 28, 1976, without any identifying documents.

L. Ron Hubbard was furious at the news, shouting, "That stupid fucking kid!

[3]: 344 Although a hose connected to the tailpipe was found in the car's window, a test for carbon monoxide was negative.

[7] Mary Sue Hubbard told Scientologists that Quentin had died from encephalitis.

[2]: 214  L. Ron Hubbard is said to have deteriorated rapidly after Quentin's death, becoming dishevelled and increasingly paranoid.