Jack was born in 1922 in Leeds, the son of Saul and Ada nee Rubenstein. In 1939 the family were living in Leeds and Saul was working as a hat and cap factory manager.

Jack died in Barnstaple, Devon whilst based at RAF Chivenor. The North Devon Journal – Thursday 20 Sep 1945 gave details of Jack’s death.

DEATH BY MISADVENTURE Barnstaple Inquest on Airman. The circumstances surrounding the death of an airman, Corporal Jack Cohen, of Chivenor aerodrome, who received fatal injuries when a collision occurred on Saturday, September 8th, between an army lorry and the pedal cycle that he was riding on the Barnstaple- Braunton main road.
Driver H. S. Underwood, 88th Light A.A. Regiment, Braunton Camp, said he was sitting beside the driver of the army motor lorry that was involved in the accident, which occurred about 11.40 p.m. The lorry was proceeding in the direction of Braunton. Witness heard a bump and the driver put on his brakes. Witness got out and found a man lying on the road suffering from facial injuries.
Witness added that he afterwards found that the cycle had no rear lamp or reflector. Dr. Natalie Blumenfelt. house -surgeon of The North Devon Infirmary, said that when admitted the airman was suffering from compound depressed fracture of the skull: with lacerations of the face, and a fracture of the left scapula and abrasions. He died at 9.40 p.m. on Friday, September 14th.

The foreman of the jury (Mr. A. E. Collings), announcing that the verdict would be “Death by misadventure.” said they exonerated the driver from fault. They added a rider that the attention of the R.A.F. should be brought to the fact that no cyclist should be allowed to ride without rear red light.