A boilermaker died in an explosion near a production shaft of Sasol's Middelbult Colliery in Secunda on Thursday morning, the petroleum giant said.
Spokesperson Johann van Rheede said Ryno Olivier, 20, who was employed by Ukhozi Mining (Pty) Ltd, died on the scene of the accident when a container used for storage of oxygen and acetylene bottles exploded on surface.
Two other contractors and four Sasol mining employees also sustained slight injuries.
The exact cause of the explosion is still unknown, van Rheede said.
The outcome of the official investigation was still sub judice.