William was the son of Alan and Alice Bell of Cambridge. After schooling, he became a survey cadet and then enlisted in 1914 at the age of 17. He became a Bombardier in the New Zealand Field Artillery, serving with the 15th Artillery Battalion.
He embarked on the 27th of May, 1916 from Wellington as part of the 13th Reinforcements travelling on HMNZT 54 or 55 the SS.Willochra or SS.Tofua bound for Suez, with the eventual destination in the UK of Plymouth or Devonport.
He went to Belgium, served in numerous actions and died in action on the 31st of July, 1917 aged only 19 in the Ypres salient. His unit was supporting an attack at La Basse Ville, in an artillery engagement trying to knock out German batteries around Warneton near Messines. The German artillery were also trying to knock out the New Zealand batteries in a deadly contest that lasted from late afternoon until about 9.30pm. William was one of the unit casualties.
He is buried in Coxyde Military Cemetery in Belgium, Block III, Row A, Grave 13