By 26 May the BEF was cut off and the decision was made to evacuate it through Dunkirk (Operation Dynamo). On 27 May 42nd (EL) Division was ordered to withdraw from the canal line to the River Lys, and the following day to the River Yser, defending the south side of the Dunkirk 'pocket'. The division completed its evacuation on 31 May. During the withdrawal 42nd (EL) Divisional Signals had lost three men killed, seven wounded, and one missing.