AMAGA, Colombia — Relatives held a resigned vigil Thursday outside a coal mine in northwestern Colombia where dozens of miners were trapped and feared dead after an explosion that killed at least 16 workers.
The fiery blast at the San Fernando mine, believed caused by a methane gas buildup, tore through an access tunnel that is some 1.2 miles (about 2 kilometers) long and drops to a depth of 500 feet (150 meters). Officials said there were 70 to 80 workers in the mine at the time.
Provincial disaster coordinator John Rendon said the Wednesday night blast collapsed part of the tunnel. But Antioquia state mining secretary Nicolas Lopez said rescue workers who had been able to get 700 meters into the tunnel and had found it intact.
The tunnel has cement-reinforced steel arches, he said, but high levels of methane and carbon monoxide were impeding the entry of rescue workers down to extraction areas where most of the trapped workers were believed located.
A shift change was in progress when the explosion occurred, officials said, adding that two injured workers managed to escape.
"I felt the explosion and it lifted me up. I felt the flames on me," a surviving miner, 31-year-olld Walter Restrepo, told RCN Television from a hospital bed where he was recovering from burns.
Lopez said the mine's ventilation system was damaged in the blast but had resumed operation. There was no way to communicate, however, with the trapped miners to know if any were alive and receiving oxygen.
Rescue efforts were called off at dusk and anxious relatives of the missing workers who had converged on the site moved to a nearby sports arena where the bodies were collected for identification.
"It's impossible that anyone is alive," said Diana Sepulveda, 28, whose husband, 25-year-old Wilson Salinas had begun work at the mine just eight days earlier.
"If the explosion didn't kill him, the gas did because it was very dense," Sepulveda said, sobbing.
About 100 rescue workers were on the scene in rugged coffee-growing mountains in the municipality of Amaga just south of Medellin, the state capital.
Earlier in the day, President Alvaro Uribe said in a statement announcing the confirmed deaths that the miners faced "a very difficult fate."
Relatives of the missing miners said working conditions in the mine were generally good but tended to get very hot – about 40 to 45 degrees Celsius (104 to 113 degrees Fahrenheit)
Mining Minister Hernan Martinez said the mine's records indicate it lacked a methane ventilation pipe and gas detection devices – basic safety features in all coal mines, where methane gas buildup is common.
Lopez said the mine complied with the minimum state requirements set by the state Institute of Geology and Mining. However, the institute said in a news release that experts inspected the mine last month and found it "didn't have gas detection devices, one of the fundamental requirements to guarantee safety in case of an explosion."
Jorge Buitrago, general manager of mine owner Carbones San Fernando, was asked whether the mine complied with safety requirements for the monitoring and control of gases.
He told The Associated Press "we complied with the conditions" but refused the elaborate.
Most mine explosions are caused by a spark or short-circuit of a motor.
Amaga's mayor, Auxilio Zapata, said about 450 to 480 people work at the mine at any one time. It was not immediately known whether that number is reduced during the night shift. Relatives said workers at the mine earned about $600 a month.
At least nine workers were killed at the San Fernando mine last August.
The biggest loss of life in a mining accident in modern Colombia occurred in 1977 when 85 people died in another mine in Amaga, also in a gas explosion, said Tomas Charris, a Uniandina University researcher.
San Fernando is one of 3,000 subterranean mines in Colombia that produce 6 million metric tons of coal a year, said Jorge Martin Molina, an engineer in the mining department at Colombia's National University.
Colombia produces 75 million metric tons of coal annually. Its biggest coal mine is Cerrejon, an open pit in the country's northeast that produces some 30 million tons a year.
Associated Press Writers Vivian Sequera, Cesar Garcia and Luisa Fernanda Cuellar contributed to this report from Bogota.