Over 120,000 British, Indian and Australian troops became prisoners-of-war. Percival was eventually liberated and he returned to Britain. Others were less fortunate.
The story of the fall of Singapore is ably told in the book Singapore 1940: Britain’s Greatest Defeat—by Alan Warren (Talisman, 2002). The front cover of the book shows Lieutenant-General Percival carrying the Union Jack en route to surrendering to the Japanese commander, Lieutenant-General Tomoyuki Yamashita.
If poor decisions on the part of British commanders were partly to blame for the defeat, so too were the lack of air cover, the lack of naval support [HMS Prince of Wales and HMS Repulse having been recently sunk], and Britain’s inadequate resourcing of her far-eastern empire [with the more crucial Middle-Eastern and Russian theatres understandably having precedence for supplies].