Alfred was born on 4 November 1915 in London to Russian born Woolf and Leah nee Warshafsky and he had two sisters Rebecca and Lotte. Their father worked as a tailor machinist and in 1939 Alfred was working as a hairdressers assistant.

Alfred was a wireless operator on Catalina JX252 which departed RAF Castle Archdale, County Fermanagh, Northern Ireland on a training exercise. The aircraft was was scheduled to land on the Lough Erne but due to a visibility reduced by foggy conditions, the pilot misjudged Lake Navar with the Lough Erne. On approach, the seaplane hit a mountain and disintegrated. All nine crew members were killed.

Nav, Sgt John Rew
Pilot, F/Sgt Noel George Edward Ladbrook
Nav, Sgt Bernard Alfred Rosentreter.
Sgt Alfred Sonenthal
W/O Reginald William Shallis
Nav, Sgt David Henry Pidgeon
A/G, Sgt Kenneth Percy West
A/G, Sgt Edmond Thomas Crow
F/E, Sgt James Pringle