Leonard was at work at the Robin Adair Ironworks in Kalgoorlie, Western Australia, along with another man named named Moiler.
They needed to break apart a brass piston cylinder, and decided to heat the hermetically sealed head in the flames of the blacksmith fire.
Moiler left Johnson holding the piston.
Soon after, an explosion threw Johnson five metres and scattered live coals everywhere.
When the remains of Johnson’s body were picked up, his clothes were still on fire.
“The lower portion of his abdomen had been torn away, his right leg was severely broken and almost taken off, and he sustained many other terrible injuries about the head and body”.
Moisture within the piston expanding in the heat was blamed for the explosion, which also sent debris hurtling into the street. One portion shot through the galvanised iron building, and struck the veranda of a house 80 yards away.
Another just missed hitting the driver of a passing steam roller.
Leonard’s mother lived nearby and rushed to the scene when she heard the explosion and there was a “pathetic scene when she was informed that her son had been killed’’.
Johnson’s grave is in the red dirt of the Kalgoorlie cemetery
Sources: Barrier Miner (Broken Hill, NSW : 1888 – 1954) Thursday 28 January 1915 p 2
Kalgoorlie Miner (WA : 1895 – 1954) Tuesday 2 February 1915 p 3