Rescuers started drilling a hole late on Friday into a smoky coal mine to help locate two miners trapped after a conveyor belt caught fire deep underground in the second major mining accident in West Virginia in less than three weeks.
More than a day after the fire broke out, crews planned to drill 60m into a section of the mine and try to contact the men by pounding on the steel drill bit.
If they receive no response, rescuers planned to drop a camera and microphone into the hole, said Jesse Cole, an official with the Mine Safety and Health Administration.
Six teams were underground searching for the men, whose exact location was unknown, said Doug Conaway, director of the state Office of Miners' Health Safety and Training.
The missing men were equipped with oxygen canisters that typically produce about an hour's worth of air.
The fire broke out on Thursday night at the Alma No. 1 mine. Rescuers were hampered by heavy smoke that cut visibility to less than a meter. After the blaze was brought somewhat under control Friday, rescuers spread out to search four tunnels, each about 6km long. The mine extends as much as 270m below ground.
About 20 rescue teams from four states were at the scene on Friday night. Those rescuers in the mine were finding some pockets of fresh air, but Conaway said there was no way to tell if conditions had changed since Thursday night.
David Roberts, co-manager of Refab Co, a mining machinery repair company, said a friend on a mine rescue team told him it was very hot and smoky inside the shafts.
Twenty-one miners were in the southwestern West Virginia mine on Thursday when a carbon monoxide monitor about 3,000m from the entrance set off an alarm. Nineteen of the miners escaped.
Rescuers had hoped to use special phones that emit sensors to try to locate the missing men, but the terrain was too rough to use them.
The governor was with the miners' families, who along with friends and co-workers gathered at a Baptist church to wait for news. Reporters were barred from the church.
Earlier this month, the governor joined another group of miners and relatives of those trapped after an explosion at the International Coal Group's Sago Mine, on the northern side of the state. Twelve miners died in the disaster. The sole survivor, Randal McCloy Jr, 26, remained hospitalized in a light coma on Friday.
"Sago is very fresh in everybody's mind, but this is a different scenario," Manchin said.
He said the families were hopeful, but he added, "They know that the odds are a little bit long."
The governor said two widows who lost husbands in the Sago mine came to the scene with their children to visit families of the missing men.