Source: August 1917 casualty.
See A Swim Binds Two Soldiers in Time for an article about this soldier.
PTE. ROBERT H. GRAHAM
A telegram has been received by Mrs. Graham, of 15 Delaware avenue, stating their her second son, Private Robert Henry Graham, was killed in action. Her other son, Pte. John W. Graham, died of wounds, September 16th, 1916. Pte. Robert Graham enlisted in July 1915, and went to France in January, 1916. He was wounded in the chest in April and in the face on September 17th, which was the day after his brother had died of wounds. Pte. Robert Graham was 24 years old and a member of the Diamond Jubilee No. 913 L.O.L. Pte. J.W. Graham enlisted in August 1915, and went to France in June 1916. He was 25 years old and was survived by his widow and baby girl. Both boys were born in Toronto and attended Fern avenue Public school. They were members of the Dunn Avenue Presbyterian Church.
Toronto Evening Telegram. Sept. 4, 1917
PTE. R.H. GRAHAM
Pte. R.H. Graham is officially reported killed in action on August 17. His parents live at 15 Delaware avenue, and this is the second son killed, the other being Pte. J.W. Graham. He was twice wounded. He enlisted in September, 1915, and is a member of Orange L.O.L. 918.
Toronto Star. September 4, 1917.
History of the 18th Battalion CEF, "The Fighting Eighteenth" 