On 8 May 1992, the Royal Observatory of Hong Kong recorded 109.9 mm rainfall from 6 o'clock to 7 o'clock in the morning, breaking the hourly rainfall record on 12 June 1966. The torrential rain caused over 200 cases of flooding and many landslips. Road traffic was paralysed. Some roads in Admiralty were turned into rapids washing several people away. However, the Education Department did not announce school closure until 11 am, so many students braved the elements to go to schools, but some of them only found on arrival that their schools were closed, and parents were confused and worried for the safety of their children. Five people, including two children, were killed by landslides, lightning and rapid flooding. Because of this rainstorm, the Observatory proposed Hong Kong rainstorm warning signals which included three colours, amber, red and black. The amber signal were the first stage of the warning system based on forecast of heavy rainstorms, and were used to alert government departments and major public transport and utility services. The red and black signals were the second stage of the warning system based on actual rainfall levels recorded, and were issued to the public.