Durban- Twenty-one SA Navy personnel have been released from hospital after they tried to save six people killed by a methane gas leak at the Durban Naval base, a spokesperson said on Friday.
Three Navy officers and three public works department employees died when they inhaled methane gas in what was described as a "freak accident", spokesperson Rachel Dulamo said.
The cause of the leak was being investigated.
The names of the three officers would be released once their families had been informed.
The labour department said the three public works personnel were repairing a pump storage unit in a 5m-deep pit when they struggled to breathe.
The officers were overcome when they tried to help them.
Paramedics declared all six dead on the scene.
In a statement, President Jacob Zuma expressed his sadness and extended his condolences to the families affected.
“We are devastated by the deaths of these hard-working soldiers and their colleagues. It is really tragic for all of them to lose their lives in this manner. This is a most painful and traumatic time for all the families and for all of us," Zuma said.