Like many other mine operators, Massey frequently sidesteps hefty fines by aggressively appealing safety violations at the mine, according to an Associated Press analysis of mine safety records.
Rescuers hoped the four miners might somehow have reached a chamber where they could survive for four days, though they acknowledged the odds were against them. Rescuers banged on a drill pipe for about 15 minutes after the first hole was complete but got no response.
Family members could do little but wait.
"They know the odds are not in our favor because of the horrificness of the horrendous blast that we had," Gov. Joe Manchin said at a briefing Wednesday morning.
Alice Peters said she was told her 47-year-old son-in-law, Dean Jones, was among the missing, though Massey said Wednesday it does not know which four miners might be alive.
Seven bodies were pulled out after the explosion, and two miners were hospitalized. Manchin said Wednesday that one was doing well and the other was in intensive care. Eighteen bodies remained in the mine, but emergency workers were only able to identify four before poisonous gas forced them out Monday.
Peters said Jones' wife, Gina, has been at the mine site since the explosion and will not leave.
"She's not doing too good," Peters said. "They told them to go home because they weren't going to let the mine rescuers back in. They're still drilling."
Crews later planned to set off small explosions on the surface to send a seismic signal to the mine. Miners are trained to bang back on the drill's casing, and sections of mine roof contain numerous metal bolts that trapped miners can bang on to signal their presence.
It was not clear how long it would take to vent enough methane so rescuers can enter the mine, but once they do it could take less than two hours for a team to get far enough inside to check for survivors, depending on conditions, said Kevin Stricklin, a Mine Safety and Health Administration official. They would be about 1,000 feet below the surface, and at least a mile-and-a-half from the entrance.
The quality and quantity of coal produced at Upper Big Branch make the mine one of gems of Massey's operation. The mine produced more than 1.2 million tons of coal last year and uses the lowest-cost underground mining method, making it more profitable. The mine produces metallurgical coal that is used to make steel and sells for up to $200 a ton -- more than double the price for the type of coal used by power plants.
U.S. Rep. Nick Rahall, a Democrat whose district includes the mine, said Wednesday that at least three Upper Big Branch miners had come to him since the explosion to say they were concerned about methane levels.
"The feelings were that they were not walking into a safe working environment," he said. They asked that their identities be kept secret because they feared losing their jobs.
Federal regulators probing the explosion plan to review Massey's safety violations, many of which involved venting methane gas. If the odorless, colorless gas is not kept at safe levels, a small spark can ignite it.
Massey is still contesting more than a third of all its violations at the Montcoal, W.Va., mine since 2007. In the past year, federal inspectors have proposed more than $1 million in fines for violations at the mine. Only 16 percent have been paid.
Bombarding federal regulators with appeals is an increasingly common industry tactic since the 2006 Sago mine disaster that killed 12 led to stiffer fines and new enforcement to punish the worst offenders, according to AP's review of records from the Mine Safety and Health Administration.
In an interview Tuesday with AP, Massey CEO Don Blankenship downplayed the link between the ventilation system and the accident.
"I don't know that MSHA thought there was a problem," he said.