A 30-year-old man with a knife locked himself in a room in a flat at Block 172 Hougang Avenue 1 on Saturday morning (Sept 9). In response to a Stomp query, the police said they received a call for assistance at the address at about 10.55am "As it was assessed that the man might pose a danger to himself, officers from Ang Mo Kio Division, the Crisis Negotiation Unit, Special