Japanese Invasion of Singapore - How it all started

From 7 February to 9 February of 1942, the Japanese managed to invade Singapore, despite the watchful eyes of the...

Australians
Soon after nightfall on 7 February, 400 men of the imperial Guards Division landed and took Pulau Ubin in a feint attack. they encountered minimum resistance. Through large troop movements in the rubber plantations across Johore had been sighted earlier, no action was taken as Percival received the news only hours before the attack.
The Japanese artillery began intensive firing the next day and Japanese pilots began bombing military headquarters within the western sector. Telegraph and telephone communications were destroyed in the bombardment. By nightfall, communications throughout the northwest defence areas were in shambles and communications between the frontline and command headquarters were broken.
On the night of 8 February, Japanese troops of the 5th and 18th Division began to cross the water using sea craft hidden near the water's edge. These were launched in the backwaters of Skudai, Danga, Perpet and Melayu rivers. This first assault was repelled by Australian machine-gunners, but other sea craft were able to seek and infiltrate gaps of the defence line.
By the third wave, the Australians were outnumbered as machine-gunners soon ran out of ammunition and the troops were crippled by the breakdown of communication with their command headquarters.
At midnight, a red starshell burst over the Straits, indicating the 5th Division's successful landing on Singapore soil. A white starshell burst later, confirming the 18th Division's success.

British
On 7 Feb, 400 Japanese soldiers took Pulau Ubin in the Straits of Johore as a manoeuvre to draw British attention to the eastern part of Singapore. Japanese planes and artillery then proceeded to bombard Singapore before troops charged down from the northwest, away from the 18th Division, the largest defending British force stationed in the northeast. British defensive positions along the northwestern coastline were swiftly overrun and by 9 February 1942, the 5th and 18th Japanese Divisions had landed north of Pasir Laba, and had taken the Tengah airfield. British forces fought to hold the Kranji-Jurong Defence Line while Japanese forces continued to push inland and succeeded in breaching British defence in northwestern Singapore.