ref. "The Covert War" by Peter Stiff
"At Ogongo Agricultural College in Ovamboland, a labourer went down into a sewage pit to clean it. His supervisor, Mr. Brown heard him fall into the water and climbed down to help him. Three Medical Service National Servicemen were in the area and tried to save them. None of them returned as all were overcome by fumes. The three, Ptes FJ Smith, JC Jooste and B van D van Papendorp were awarded Honoris Crux medals"