Harwich based submarine E22 was sunk by German U-Boat UB18 on the morning of 25th April 1916 off the Suffolk coast.
31 crew appeared to have died as a result of the torpedo fired by UB18. 2 crew were picked up by UB18 (Frederick Buckingham and William Harrod) and taken to Zeebrugge as Prisoners of War.
What makes E22 unusual is that it was a submarine fitted with 2 Sopwith Schneider aircraft for use intercepting Zeppelins. E22 had been in a group of 4 submarines travelling on the surface when attacked by UB18.
The following day, UB18 captured and scuttled the Alfred off the coast of Lowestoft. No casualties were inflicted.
UB18 was herself sunk in December 1917.