David Koch, a billionaire conservative backer, dead at 79

Charles Koch, Koch Industries Inc’s chairman, disclosed the death in a statement that touched on his younger brother’s lengthy battle with prostate cancer and his philanthropic contributions to medical research, education and the arts.“He will be greatly missed, but never forgotten,” Koch said in a statement addressed to employees. “David was proud of the extraordinary work you all have done to make Koch Industries the successful company that it is today.”WATCH: Trump criticizes Koch brothers, tweeting they are a ‘total joke in real Republican circles’ Koch, a philanthropist and patron of cultural and medical institutions, amassed his vast wealth with a large ownership stake in Koch Industries, the Wichita, Kansas-based company he ran with Charles.With Charles as chairman and chief executive and David as executive vice president, Koch Industries – one of the world’s largest privately-held businesses – aggressively expanded beyond the oil refining business their father created into an array of new ventures.David Koch stepped down from the business and political activities in June 2018, citing declining health.