I was curious about how he actually died and found an [1] article describing it:

> Kahneman used the services of Pegasos in the village of Roderis in Nunningen, Switzerland. In the death room with a view over green hills, wearing a suit and tie, he lay on the bed and turned on an infusion of sodium pentobarbital himself. A companion held his hand and told him they were holding it on behalf of his loved ones. Kahneman's last words were "I feel their love."

[1]: https://www.aargauerzeitung.ch/schweiz/suizidhilfe-weltstar-...