With their heavy guns pointed uselessly to the south, British forces under the command of Lieutenant-General Arthur Percival failed to anticipate a Japanese invasion from the north.
The Imperial Japanese Army, riding in on bicycles, took the British by surprise and managed to capture Singapore in just 70 days.
Or so many falsely believed. While the 70-day time period is correct, this version of events is one of several popularly-held myths debunked at the refurbished Battlebox at Fort Canning Hill.
According to historical sources, Lt-Gen Percival had anticipated a northern attack on Singapore as early as 1937.
He stationed six brigades of troops in the north-east, but the north-west, where the Japanese struck with the bulk of their total forces, was only lightly defended by two less experienced brigades.
The new operator of Battlebox - Singapore History Consultants - officially reopened it yesterday with new generators and air-conditioning. Information panels and guided tours have also been reworked to present a more balanced and coherent narrative.
"For too many years, our schoolchildren have focused on getting a deep appreciation of the years of Occupation," said Mr Jeya Ayadurai, director of Singapore History Consultants. "We've understood what it means to be victims, but there has been little understanding of what caused that occupation."
The narrative will also touch on the military prowess of Lt-Gen Tomoyuki Yamashita and the Japanese army. Tour guides will emphasise that the fall of Singapore was inevitable, and that Lt-Gen Percival had little choice but to surrender.
"Telling more than one side of a story is really the only reasonable way to present history," said Professor Brian Farrell, who specialises in military history at the National University of Singapore.
Yesterday's opening event was also attended by Japan's Ambassador to Singapore, Mr Kenji Shinoda.
He said: "I am reminded of the significance of working together for the cause of enduring peace for humankind, to ensure that what happened 75 years ago will never be repeated."