Green’s Dictionary of Slang

answer the last roll-call v.

to die.

1893		Leeds Times 23 June 3/4: Another of the old soldiers of the Crimea has gone to answer the last roll-call.
1900		Sth Wales Echo 30 Nov. 2/8: Out on the veldt [...] lies the body of his master who has gone to answer his ‘Last Roll-Call’.
1918		Kirkintilloch Herald 27 Nov. 1/1: In Memoriam [...] Killed in action, my eldest son [...] Awaiting the sound of the trumpet to answer the last roll-call.
1936		L. Pound ‘American Euphemisms for Dying’ in AS XI:3 199: Answered the last roll call.