Chandigarh, Sep 20 (ANI): Lt General (Retired) PN Hoon on Friday launched a frontal attack on former army chief General VK Singh, against whom an enquiry has been ordered for setting up a special unit in the army headquarters to allegedly topple the Jammu and Kashmir Government and said the incident was a sad day for the armed forces. Hoon also said that former chief VK Singh was known for his tarnished reputation for some time now.