A suspected burst valve which led to the collapse of a crude oil storage tank at Willowton Oil Mills in Ohrtmann Road left six workers injured and sent about 240 tons of effluent flooding the Baynespruit tributary of the Duzi River.
Video footage shows dead fish floating on the river's surface after the spill.
Environmental experts described this as one of the worst incidents of pollution the city had ever seen.
A local private hospital confirmed the six workers who were injured were in a stable condition yesterday. “The ... men were all treated for smoke inhalation, abrasions, cuts and physical injuries. Three were taken into the general ward, while the other three were [initially] taken into ICU because of the severity of their injuries,” said a spokesperson.
Msunduzi Municipality spokesperson Thobeka Mafumbatha said subsequent to the first incident two additional tanks containing fatty acids and caustic acid were dislodged, resulting in a cocktail of the three substances flooding the premises and spilling out into the river.
Read more: Toxic sludge chokes Duzi.