Two men are in a critical condition and another seriously injured after being overcome by chemical fumes at Umhlanga on Thursday. The men were working in a drainage system at Gateway. Rescue Care Paramedics arrived on scene to find the three men unconscious, said managing director Garrith Jamieson."Immediately more ambulances and Advanced Life Support Paramedics were dispatched to assist as well as Durban Fire Department, SAPS and Metro Police Search and Rescue. "Once rescue equipment arrived, paramedics Tebogo Dladla and Paul Herbst used breathing apparatuses and went down to rescue the men. The men were brought up using a roping system," said Jamieson. They were brought to the surface using a rope and assisted by advanced life support paramedics. "Two men were in a critical condition and were placed on manual ventilators while the third man had sustained serious injuries. The men were then rushed to hospital."At this stage the exact events leading up to the incident are unknown, however, SAPS will be investigating further," said Jamieson.