Horace L. Hunley, Cowper P. Coles and John Day all have a shared event in their lives, what was it?

Each listed inventor has the unfortunate distinction of being killed by their own creations. Horace Lawson Hunley (born 1823, died 1863) invented the first combat submarine for the Confederate States of America during the Civil War. While testing his design in 1863 Hunley and seven other men drowned.

Cowper Phipps Coles (born 1819, died 1870) was a Royal Navy officer and designer of an early masted warship (one that could move by sail or by the steam engine) with turret guns, the HMS Captain. While the ship was cruising off the coast of Spain as part of a naval squadron of 11 ships, high winds and the continued use of sail capsized the ship, killing Coles along with 480 men. Only 27 survivors were recovered.

John Day (born ca. 1740, died 1774) developed a "diving chamber" (or sometimes referred to as an unpowered submarine). While off the coast of Plymouth, England, Day was locked in the chamber with food, water, a candle and a hammock. His expectation was to descend about 130 feet using two 10-ton weights to sink the chamber, and remain there for about 12 hours. When released from the support ship, his chamber sank into the sea, never to return.