A private security guard committed suicide Saturday by jumping from the 11th floor of a building here, police said. This is the third such incident in the building.Hari Shankar, hailing from Bulandshahr district in Uttar Pradesh, jumped off from Park Central building in sector 30."The deceased had Saturday joined duty after Diwali vacation.... No suicide note was recovered," police said.Earlier, in separate incidents two people had committed suicide by jumping from the top of the same building."Way to top roof (11th floor) was locked by police after the two incidents. We are inquiring how the guard managed to reach there," police added.