After retiring, Waibel became chairman of the bank of Ernst Brunner, a businessman who had become rich in penicillin trading. In 1970, the bank collapsed. Waibel gave a farewell Christmas party and then shot himself.  60 years after the end of the war, a memorial plaque was inaugurated in the presence of his family at the Army Training Center in Lucerne. Present was the Swiss Federal President Samuel Schmid and the ambassadors of the US, Russia, France and Italy. In his speech, former Secretary of State Franz Blankart said that Waibel would have been stopped by the Federal Council, had they known about his activities. The inscription on the plaque reads:  As mediator between the German and the Allied warring parties he reached, in Lucerne on 2 May 1945, a truce in northern Italy. Courageous and opinionated, obeying not commands but his own conscience, he lit the beacon of peace which brought the war in Europe to an early close. Innumerable human lives and noble cultural assets were spared, Northern Italy escaped the barbaric war atrocities of the scorched earth.