JOHANNESBURG, Soouth Africa -- Rescue teams Saturday recovered the last four bodies of 53 miners killed when a methane gas explosion ripped through a South African coal mine.
Rescuers had been working through rubble and debris since Thursday afternoon in an attempt to find survivors of the explosion at the Middelbult coal mine in the small town of Secunda, about 75 miles (120 km) southeast of Johannesburg.
Inspection teams are expected to enter the mine later Saturday to determine the cause of the explosion, which occurred at a depth of 425 feet (130 m) and started an underground fire.
The disaster was the country's worst mining accident in recent years and the fifth worst in South Africa's mining history. The worst accident was in 1960 when a methane gas explosion at a mine in the country's Natal province killed 435 workers.
Labor unions, backed by the African National Congress, have called for a commission to investigate mine safety and the introduction of drastic measures to protect the lives of the country's miners, most of whom are black.
'(Mining in South Africa was) probably the most dangerous in the world because of the failure to make safety measures adequate to the difficult conditions under which we mine,' the Congress of South African Trade Unions said in a statement.
Other trade unions accused the white-owned mining companies of seeking profits at all costs.
President Frederik de Klerk promised a full investigation into the latest accident but said the reality of mining accidents had to be accepted.
'The nature of the challenges facing this industry lend themselves to sudden and tragic events such as have now occurred,' de Klerk said in a statement issued by his office.
Last year 520 gold and coal miners lost their lives and about 9,000 were injured in mining accidents. Most of the accidents were attributed to rockfalls.