Notes
The Roll lists him as "Walter Phillips" whose address it records as "Late of 90 Cromwell Road". The original 1921 version of the Roll recorded his regimental number as 50800; this 1994 version omitted his regimental number. Both versions state that he served in the "3rd Northants" and that he drowned on an unspecified date.
(The family living at 90 Cromwell Road on the 1911 census was Edward James and Mary Ann Phillips, with 9 of their 12 surviving children. [One of the sons living with them on that census, Alfred, died in WW1 and is named on the Peterborough Roll of Honour]. On the 1901 census the family had been living at Bradbury Street in Radcliffe, Lancashire; at that time, Edward and Mary Jane's son Walter was living with them, who was stated to be aged 8, born in Kensington. Although he had left home by the time his parents were listed at 90 Cromwell Road in Peterborough in 1911, he would therefore be the Walter Phillips of that address to whom the Roll alluded. He did not, however, die in WW1.
CWGC has no record of a Walter Phillips of the Northamptonshire Regiment dying in WW1, nor do the Army Registers of Soldiers' Effects or Soldiers Died in the Great War etc. There was, however, a Driver Charles William Phillips of the 1st/1st Northants Battery, Royal Field Artillery, regimental number 4368, who drowned on 1/8/1915, and is buried in Broadway Cemetery in Peterborough. On 4/8/1915 the Peterborough Express printed a report of the inquest, re his having accidental drowned while fishing in the River Nene, describing him as a Driver in the RFA who was on work furlough; his address was reported as 38 Parliament Street, Peterborough.
As the "Walter Phillips" of Cromwell Road listed on the Roll did not in fact die in WW1, it appears near certain that its mention of a casualty from the "3rd Northants" who drowned in WW1 was actually alluding to the death of Driver Charles William Phillips of the Northants Battery RFA, who drowned on 1/8/1915.