Adam Twells died as a result of an accident during training in the Submarine Escape Training Tank in HMS DOLPHIN, Gosport, however the exact cause of death has never been established.

The Grantham Journal dated Friday 21 July 1995 reported  “Naval exercise ends in tragedy.  A former Aslockton man died during an underwater Royal Navy safety exercise on Friday. Able Seaman Adam Twells, 24, was climbing 28 metres up the inside of a water tank in simulation of an escape from a submarine. Royal Navy spokesman David Healy said: “It was basic training that submariners must repeat. He’d re-qualified twice before. Those with him during the procedure tried to revive him but unfortunately he died.” He added no one had died for 20 years in the tank, at Gosport, near Portsmouth. A top-level Inquiry has been opened into the safety of both the tower and Mr Twells’ breathing apparatus, with results expected in two months. Mr Twells served with the Navy for eight years. His parents, retired Aslockton School headteacher Michael and his wife Maureen, travelled from their home in France to meet Navy officials in Scotland, where their son was based. They were too upset to talk to the press. A full military funeral is expected next week.”

The Newark Advertiser of 18 Jul 19, reporting on a new memorial unveiled in a village church, said: “Submariner Able Seaman Twells was accidentally drowned in a diving accident in 1995”