He apparently died when the helicopter he was piloting went down in fog.
-- Agence France Presse, November 1, 2002 ("Bread giant Poilane presumed dead in chopper crash"): "Lionel Poilane, head of the internationally renowned French bread-making business, was presumed dead Friday after the helicopter he was piloting crashed off his private island on the Brittany coast. Divers who traced the wreckage of the aircraft in waters near the port of Cancale said it contained a body, though they were unable to confirm if it was that of Poilane or of his wife, who was accompanying him."