A warehouse worker was bludgeoned to death as he tried to protect a female colleague from another staff member who went berserk with a hammer and crowbar in Kowloon Bay yesterday. Chan Wai-kwan, 43, and four female clerks aged 30 to 44 were attacked at about 9am as they ate breakfast at an electronics warehouse in Tai Yip Street. Police said the attacker went to a nearby public toilet to wash his hands before disappearing. A senior police officer heading the murder investigation said last night Chan had acted heroically as his colleagues had escaped with minor injuries. An emergency crew was sent to the scene when a watchman called police after hearing screams. Four hours later, a delivery worker, 45, was arrested when he went to Kowloon Hospital for a check-up. The man's brother-in-law told officers his relative had suffered mental illness and was an outpatient at the psychiatric unit of a public hospital. Sau Mau Ping district commander Chief Superintendent Tony Au Yiu-kwan said: 'The victim was struck over his head when he tried to stop the suspect attacking one of his four female colleagues. 'The other three women were also injured when they tried to run out of the office and the suspect gave chase and attacked them.' When officers arrived, Chan, who had suffered heavy blows to the back of his head and face, was found collapsed in the seventh-floor lift lobby. The women were hiding in a toilet cubicle in their fourth-floor office. All five were taken to United Christian Hospital, where Chan was declared dead. Poon Lai-kam, 40, was in a stable condition, while Cheng Tai-tei, 30, Wong Lai-chu, 39, and Tsui Mei-yee, 44, were discharged after treatment. Mr Au said the arrested man had worked with the company for about 10 years and had not been involved in any trouble or disputes with his fellow workers. Last night he was being questioned by officers of the District Crime Squad at Sau Mau Ping police station. He is married with two children and lives in Tseung Kwan O. Chan, who was unmarried, had worked with the company for more than 10 years. A spokesman for the Mental Health Association of Hong Kong, Wu Kwok-wing, said last night that services for former mental patients were extremely limited. 'After-care services are only given to former mentally ill patients discharged from halfway houses. If someone returns to society after leaving mental hospitals, he or she may not receive any after-care services,' he said.