The Rheinmetall Denel Munition building in Macassar‚ where five types of explosive propellant were being mixed‚ “disintegrated” in the blast. Eight men working inside were killed.

Sitting alongside Gordhan at a news conference at the factory on Friday‚ company CEO Norbert Schulze said the workers would have been mixing about a tonne of propellant and it would have ignited in milliseconds.

“Usually we talk about ignition like burning‚ but this was a detonation. We have no idea what caused this detonation‚” he said.

There was “hardly any evidence left” to help with the investigation‚ which would be a complicated process.

The building is one of five in the propellant production process for 155mm artillery shells‚ the largest in modern use. Schulze used a diagram to explain the process:

•  In the first building‚ different explosive materials are mixed together as a dough;
• The dough is extruded through a machine which resembles a spaghetti-making device and cut into grains;
• The grains are dried;
• The grains are mixed according to clients’ specifications‚ depending on how far they want the artillery shell to be fired. This is where the explosion happened; and
• The final building is a magazine‚ or store‚ where the charges are kept before being exported or shipped to the South African National Defence Force.

The 400 buildings at the Macassar factory are all contained by blast walls to prevent an explosion in one from causing a chain reaction.

Gordhan said 85% of the products made by Rheinmetall Denel Munition at five sites were exported‚ while the rest went to the SANDF.

The minister said the company and government were in close contact with the families of the men killed in Monday’s blast‚ and had provided immediate financial assistance.

In terms of the workers’ contracts‚ their families would be compensated for the loss of their loved ones‚ he said.