The military records on ancestry for the 1st. world war have a William James Cross from Marksville...born Aug. 15, 1876, in Barrie Ontario... enlisting on Mar.8, 1916. Next of kin is an aunt Mrs. Wesling.
He might have died overseas. There is a death record for a William Cross dated Sept. 23, 1916.
I am enclosing those documents with this reply.
Marksville is now called Hilton Beach. I hope this info helps.