Ron Wooten, director of the West Virginia Office of Miners Health, Safety and Training, said, "We have hope. We still have hope."
Officials were being especially careful, though, because of the deaths of mine rescue crew members in a secondary mine explosion in Kentucky in 1976 and in a follow-up pillar collapse, or burst, just three years ago at the Crandall Canyon Mine in Utah.
"We have to do what we think is right," Stricklin said. "We have to take away any possibility of another explosion."
After the rescue teams were pulled out this morning, workers began to pump nitrogen into the mine. The nitrogen reduces the oxygen level, which should make the air less combustible and put out the fire.
When asked why nitrogen wasn't put in earlier, Stricklin said it was, yet again, a change of plans.
"The plan was to put nitrogen in if [gases in the mine] came close to the explosive range. What we didn't expect was there to be smoke from a fire, and that changed what we had to do," he said.
In an e-mail message, though, a Department of Labor spokesman said that Massey had "dragged its feet" in having the nitrogen delivered to the mine site.
"We asked the company for it two days ago," said department spokesman Carl Fillichio. "We had to keep asking for it."
Earlier Thursday, rescue teams were pulled from the mine after a three-hour mission that got them within 1,000 feet of a refuge chamber where they hoped the miners took shelter. But the rescuers were called back from the mine Thursday morning after repeated sampling showed unsafe air quality that could cause another explosion.
Stricklin said Thursday the explosion filled the mine with an "explosive mixture" of high levels of carbon monoxide and methane, along with low levels of oxygen.
"It tells us it was a very violent explosion," he said.
Officials have said Monday's blast was likely caused by an explosion of methane gas, and was possibly fueled by the presence of coal dust.
Any chance of survival the miners had hinged on using self-contained self-rescuers, or SCSRs, to make their way to refuge chambers stocked with enough air, food and water to last four days.
An SCSR is a breathing apparatus that generates about an hour's worth of oxygen that each miner carries. In the event of a catastrophe, miners are trained to first try to get out of the mine. If they can't, the next step is to make their way to a rescue chamber and hunker down.
Rescuers made a search into the mine Monday night, but by early Tuesday were forced to pull out when they detected toxic and highly explosive gas levels underground. During that time, searchers were able to check one refuge chamber, which was empty.However, they did discover that three SCSRs had been removed from emergency stockpiles, leading rescuers to believe that at least some miners had survived the initial blast.