Cause of Death of my uncle 1911

My uncle was born in Arendal on 29 April 1911, male child of Hanne and Aksel Berntsen. Baptized "Alf Berntsen" 6 Aug 1911, Arendal. Died 18 Aug 1911, Arendal, buried 23 Aug 1911. Alf was four months old. Would his cause of death be available? Thank you for your assistance.