K Shanmuganathan, the personal assistant of the late DMK patriarch and former Tamil Nadu CM M Karunanidhi, passed away on Tuesday due to age-related ailments. The 80-year-old initially worked with the police department and started working with Karunanidhi in 1969, after the politician spotted his stenography skills. Karunanidhi's son and current Tamil Nadu CM MK Stalin condoled his demise.