JOHANNESBURG, South Africa (AP) _ Gold mining resumed today at the Kinross mine and the government began an inquiry into the fire that killed 177 men. A black miners' union accused mine operators of blatant disregard for safety.

The search continued for one man still missing from Tuesday's fire, the worst gold mine disaster in South African history. The No. 2 shaft where the fire took place remained shut down.

Five men had been reported missing this morning. But in the afternoon, a mining company spokeswoman, Beth Kilian, said there had been a mistake in the numbers. She said five men had not been missing, and rescuers were searching for only one.

Of the 183 black miners who suffered breathing problems, burns and other injuries, 14 remained hospitalized this morning, said General Mining Corp. spokesman Harry Hill. He said all 52 white miners hospitalized after the accident had been released by today.

The victims, including 172 blacks and five whites, died from breathing gases released from burning synthetic materials in a fire sparked by a welding torch.

''This disaster takes us back to the Dark Ages and demonstrates clearly the unacceptably low safety standards practiced in South Africa's mining industry,'' said Marcel Golding, spokesman for the National Union of Mineworkers, which claims about half the nation's 450,000 black gold miners as members.

He said the union has repeatedly asked that materials such as plastic piping that could give off toxic fumes if burned be removed from the mines.

Cyril Ramaphosa, the union's general secretary, said in a South African Broadcasting Corp. radio interview that the fire at the Kinross mine already has changed black miners' attitudes toward the annual wage negotiations with the Chamber of Mines.

''You don't need an expert to detect unsafe working conditions,'' he said.

Ramaphosa spent three hours Wednesday in the mine, near the town of Evander about 62 miles southeast of Johannesburg. He said the welder involved in the accident that sparked the fire did not have a fire extinguisher at hand.

''We believe this accident could have been avoided,'' Ramaphosa said after emerging from the mine.

He said the union executive planned to meet to discuss possible legal action on behalf of the injured miners and the families of the dead. Ramaphosa said about 5,000 of the 8,000 black workers at the mine were members of his union.

Hill said the No. 1 shaft at Kinross, which was shut down Wednesday along with the No. 2 shaft, resumed operations today.

He said the miners assigned to shaft No. 2 will continue to receive wages.

Kinross General Manager Jacobus Olivier said synthetic materials like the polyurethane foam used to control seepage billowed smoke through the tunnels long after the fire had been extinguished. Olivier said the General Mining Corp., the country's second largest mining group, had not known before the fire that the polyurethane foam was flammable.

The Chamber of Mines said in a statement, ''The polyurethane and other products used in mines have until now been regarded by mines as safe. But the Kinross tragedy clearly puts a huge question mark over this, which the Chamber of Mines research organization will be investigating once their role in the events at Kinross is known.''

The chamber, which groups the country's major mining firms, has not previously tested the foam, the statement said.

Danie Steyn, minister of mineral and energy affairs, toured the accident site Wednesday.

''As usual, a thorough judicial inquiry will have to be conducted,'' he told reporters. He declined to elaborate on the investigation except to say that government mining engineers would ''have discussions'' with the Department of Justice.

He said the union would be informed of developments.

Engineers studied samples of burned polyurethane foam and other charred debris today in an effort to determine the exact source of the poison gas that killed the men.

About 2,400 men were working in the mine when the fire broke out.