Wooten, the state mine safety chief, first learned of the Upper Big Branch incident in a cell phone call he received from Elizabeth Chamberlin, Massey's corporate vice president for safety and health. In an interview last week, Wooten said he wasn't sure of the time of that call.

"It broke up, but I heard her say, 'this is very serious,'" Wooten recalled.

Wooten called one his top staffers, Terry Farley, and that call began a cascade of further phone calls. A full timeline of those calls has not yet been made public.

Wooten said his agency's records indicate that no official rescue teams went underground until after 7:30 p.m. -- four hours after Massey first reported the problem to MSHA and the state.

But Massey says one of its in-house teams was at the mine by around 4 p.m., and federal records indicate teams were underground by at least by 6:15 p.m., and perhaps as early as 5:30 p.m.

Meanwhile, though, a crew of six miners led by Chris Blanchard, president of Massey's Performance Coal subsidiary, and Jason Whitehead, director of underground operations, were in the mine for several hours between the time of the explosion and the time official rescue teams were deployed.

Investigators have questioned what Blanchard and Whitehead were doing, and both men have been asked to testify about their activities underground.

Harvey said Blanchard and Whitehead first encountered miner Timothy Blake, who had survived the explosion but was dazed, and helped him out of the mine.

Then they continued into the mine, discovering a mantrip that had been carrying eight miners out of the operation at shift change. The six miners traveling with Blanchard and Whitehead took those miners out, Harvey said. Two of those workers initially had survived, but one of those two, along with the six others who were dead at the scene, later died.

Harvey said that Blanchard and Whitehead remained underground, attempting to reach an airtight rescue chamber near the longwall section. "Subsequently, they did locate victims at the longwall who did not survive," Harvey said.

It's not clear exactly when the three possible survivors -- one of whom later died -- reached the surface. MSHA's draft timeline lists two possible times -- one between 4 p.m. and 5 p.m. and another at 7:26 p.m.

Emergency response records from Raleigh County, however, indicate that the mine asked for helicopter service at 4:44 p.m. to transport three potential survivors who "are now at the surface."

Throughout the evening, the reports varied about how many miners had died and, more importantly, how many might still be trapped underground waiting for rescuers.

At about 5:14 p.m., a state Homeland Security dispatcher called Massey officials to try to get details about possible injuries.

"I've heard anywhere from 200 men underground," the dispatcher told Massey spokesman Jeff Gillenwater. "I've had 50 people injured. I've had 20 people dead on the scene."

Gillenwater referred the dispatcher to a Massey press release, issued at 4:57 p.m., that said "information about injuries is uncertain at this time."

The dispatcher responded, "When you get something, my director is all over my backside wanting information."

Massey's first public confirmation of any deaths came shortly after 8 p.m., in a press release that reported seven miners had died and 19 were "unaccounted for" at the mine.

But as early as 5:02 p.m., a Performance Coal official had told the Raleigh County 911 office that the company had counted at least 28 miners missing.

At 10 minutes after midnight, Labor Department officials issued their own news release, announcing that 12 workers had died, two were hospitalized and 17 unaccounted for.

That release appears to be the first count that contained the right figure -- 31 -- for how many miners had been either killed, injured or were still missing.

But in an interview with investigators, MSHA's Bob Hardman said that at 12:22 a.m. -- 12 minutes after that news release -- agency officials were still trying to get an accurate count.

An hour and 20 minutes later, Massey issued a statement to announce 25 miners had died and four more were still unaccounted for. Four days later, those four were found, also dead.

Reach Ken Ward Jr. at kw...@wvgazette.com or 304-348-1702.

CHARLESTON, W.Va. -- Shortly after 3:30 p.m. on April 5, a Massey Energy official called West Virginia's industrial accident hot line to report what sounded at the time like a relatively minor problem at the company's Upper Big Branch Mine in Raleigh County.

"I want to report an emergency," the caller said. "It is an air reversal on the beltlines."

The Massey caller reported increasing levels of carbon monoxide gas, but said there were no injuries. The mine was being evacuated as a precaution.

"Thank you, sir," the operator said. "You have a great day."

"You do the same," the Massey official responded.

It would turn out to be anything but a great day for Massey Energy and especially for the families of 29 miners who died in what turned out to be the worst U.S. coal-mining disaster in 40 years.

Within an hour, Raleigh County emergency officials were warning of at least 10 injured. Reports from various emergency agencies quickly spread, indicating that many miners might be dead.

But over the next eight or nine hours, solid information was hard to come by, even for mine rescue and emergency officials charged with responding to -- and trying to rescue any survivors of -- the massive explosion deep underground.

More than five months after the Upper Big Branch Mine Disaster, federal and state investigation teams are still struggling to put together even a basic timeline of the events of those crucial hours after the blast.

When did the explosion itself occur? How quickly after that did Massey realize the gravity of the situation? When did specially trained mine rescue teams first make it underground? How long did it take for those teams to learn exactly how many survivors they were searching for?

"I think there was an awful lot of confusion as to what was going on," said Ron Wooten, director of the West Virginia Office of Miners Health, Safety and Training.

Internal Massey records, government documents and interviews reveal a variety of conflicting information that investigators might not be able to sort out for months -- if ever.

For example, in a briefing 10 days after the explosion, Labor Secretary Hilda Solis told President Obama that the explosion happened at 3:02 p.m.

Solis and Joe Main, assistant labor secretary for the U.S. Mine Safety and Health Administration, said carbon monoxide alarms had triggered underground at that time "indicating this was the likely time of the explosion."

But internal Massey monitoring data obtained by the Gazette includes no carbon monoxide alarms at 3:02 p.m. Instead, the data shows that carbon monoxide alarms throughout the mine began going dead at 3:08 p.m.

And reports from MSHA and the state mine safety office indicate Massey told officials at those agencies the incident occurred at 3:27 p.m.

Even a few minutes can be precious when it comes to responding to a mining accident. After response delays at the Sago Mine disaster and the Aracoma Mine fire in 2006, state and federal lawmakers required mine operators to report such incidents within 15 minutes.

Asked to explain the 3:02 p.m. report, MSHA officials initially referred back to the report to Obama. Later, in an e-mail response, MSHA district manager Bob Hardman said he listed the explosion time as "approximately 3:27 p.m. due to the uncertainty of the exact occurrence time."

A draft MSHA timeline, obtained by the Gazette, shows the agency is trying to "verify" the 3:02 time it included in its report to the White House.

Shane Harvey, Massey's general counsel, said it took some time for mine officials to determine that the "air reversal" reported to state and federal officials was caused by an explosion.

"Communication and power were lost immediately and no one knew what caused this," Harvey said. "The presence of CO, to my understanding, is not immediately reportable. Unplanned fires and explosions are, but no one knew for sure that there was a fire or explosion.

"However, the persons present quickly realized that the elevated CO levels, the loss of power and the loss of communications were very likely due to a serious problem and they reported it to MSHA -- even if they were not required to do so.

"The determination that there had been an explosion was not made until later," Harvey said. "I do not know what time."

Wooten, the state mine safety chief, first learned of the Upper Big Branch incident in a cell phone call he received from Elizabeth Chamberlin, Massey's corporate vice president for safety and health. In an interview last week, Wooten said he wasn't sure of the time of that call.

"It broke up, but I heard her say, 'this is very serious,'" Wooten recalled.

Wooten called one his top staffers, Terry Farley, and that call began a cascade of further phone calls. A full timeline of those calls has not yet been made public.

Wooten said his agency's records indicate that no official rescue teams went underground until after 7:30 p.m. -- four hours after Massey first reported the problem to MSHA and the state.

But Massey says one of its in-house teams was at the mine by around 4 p.m., and federal records indicate teams were underground by at least by 6:15 p.m., and perhaps as early as 5:30 p.m.

Meanwhile, though, a crew of six miners led by Chris Blanchard, president of Massey's Performance Coal subsidiary, and Jason Whitehead, director of underground operations, were in the mine for several hours between the time of the explosion and the time official rescue teams were deployed.

Investigators have questioned what Blanchard and Whitehead were doing, and both men have been asked to testify about their activities underground.

Harvey said Blanchard and Whitehead first encountered miner Timothy Blake, who had survived the explosion but was dazed, and helped him out of the mine.

Then they continued into the mine, discovering a mantrip that had been carrying eight miners out of the operation at shift change. The six miners traveling with Blanchard and Whitehead took those miners out, Harvey said. Two of those workers initially had survived, but one of those two, along with the six others who were dead at the scene, later died.

Harvey said that Blanchard and Whitehead remained underground, attempting to reach an airtight rescue chamber near the longwall section. "Subsequently, they did locate victims at the longwall who did not survive," Harvey said.

It's not clear exactly when the three possible survivors -- one of whom later died -- reached the surface. MSHA's draft timeline lists two possible times -- one between 4 p.m. and 5 p.m. and another at 7:26 p.m.

Emergency response records from Raleigh County, however, indicate that the mine asked for helicopter service at 4:44 p.m. to transport three potential survivors who "are now at the surface."

Throughout the evening, the reports varied about how many miners had died and, more importantly, how many might still be trapped underground waiting for rescuers.

At about 5:14 p.m., a state Homeland Security dispatcher called Massey officials to try to get details about possible injuries.

"I've heard anywhere from 200 men underground," the dispatcher told Massey spokesman Jeff Gillenwater. "I've had 50 people injured. I've had 20 people dead on the scene."

Gillenwater referred the dispatcher to a Massey press release, issued at 4:57 p.m., that said "information about injuries is uncertain at this time."

The dispatcher responded, "When you get something, my director is all over my backside wanting information."

Massey's first public confirmation of any deaths came shortly after 8 p.m., in a press release that reported seven miners had died and 19 were "unaccounted for" at the mine.

But as early as 5:02 p.m., a Performance Coal official had told the Raleigh County 911 office that the company had counted at least 28 miners missing.

At 10 minutes after midnight, Labor Department officials issued their own news release, announcing that 12 workers had died, two were hospitalized and 17 unaccounted for.

That release appears to be the first count that contained the right figure -- 31 -- for how many miners had been either killed, injured or were still missing.

But in an interview with investigators, MSHA's Bob Hardman said that at 12:22 a.m. -- 12 minutes after that news release -- agency officials were still trying to get an accurate count.

An hour and 20 minutes later, Massey issued a statement to announce 25 miners had died and four more were still unaccounted for. Four days later, those four were found, also dead.

Reach Ken Ward Jr. at kw...@wvgazette.com or 304-348-1702.