Three workers were rescued from an underground collection tank, believed to contain diesel and oil, near Wilton Crescent, Umhlanga Ridge, Durban on Thursday morning.
The workers were cleaning the tank when they were overcome by gas.
At 10.32am on Thursday morning, Netcare 911 responded to the scene, spokesperson Shawn Herbst said.
SA Police Service Search and Rescue, Durban Metro Police Search and Rescue and Ethekwini Fire and Rescue Services set up a rope and ladder system with breathing apparatus to enter the tank.
“All three patients had difficulty breathing and required advanced life support interventions to stabilise them.
“Once treated the patients were transported by various ambulance services to hospital for further treatment,” Herbst said.
All necessary authorities were on scene.