Neither man had been blamed for the disaster that killed 12 of their comrades, and neither one's family has definitively linked the suicides to the accident. But those who knew the men say there is little doubt the tragedy haunted them.
"I'm not sure anybody ever gets over it," said Vickie Boni, the ex-wife of one of them. "You live with it every day."
Both men were working at the Sago Mine on the day of the blast and had been questioned by investigators along with dozens of other witnesses. One former co-worker said at least one of the men felt investigators were treating him as if he had done something wrong.
John Nelson Boni, whose job that day was to maintain water pumps, shot himself Saturday at his home in Volga, State Police said.
William Lee "Flea" Chisolm, the 47-year-old dispatcher responsible for monitoring carbon monoxide alarms and communicating with crews underground that morning, shot himself at his Belington home Aug. 29, authorities said Tuesday.
State and federal mine-safety agencies have not determined the cause of the Jan. 2 blast. But a spokeswomen for both agencies said that both men had been thoroughly interviewed and there had been no plans to talk with them again.
Mine owner International Coal Group has said it believes a lightning bolt somehow ignited methane gas that had accumulated naturally in a sealed-off section of the mine.
Boni, who was certified as a fireboss and occasionally conducted pre-shift inspections to ensure the safety of incoming crews, told investigators he had detected low levels of methane in that area five days earlier and reported his findings to a supervisor, who was not alarmed.
As for Chisholm, he told investigators that a carbon monoxide alarm had sounded about 20 minutes before the explosion. Following ICG procedure, he alerted a crew inside the mine and asked it to verify the alarm because the system that had a history of malfunctions.
At a hearing in May, ICG executive Sam Kitts said miners are not required to evacuate when there is an alarm; they verify it, then decide how to proceed.
"The dispatcher did what he was supposed to do. He notified a maintenance person who was then able to go up and check the sensor before they would have again advanced onto the section," Kitts testified.
Friends and family said Boni retired shortly after the accident, in which the sole survivor among those trapped by the blast was a severely injured Randal McCloy Jr. Chisolm had taken a leave of absence but remained an employee, according to ICG. "We believe that Mr. Chisolm was a very good, hardworking employee," ICG spokesman Ira Gamm said.
"Our thoughts and prayers go out to each of their families," Gamm said in a statement.
Boni's ex-wife said he had never discussed the accident with her, but "I'm sure it had weighed on his mind." Vickie Boni, who divorced Boni 15 years ago but saw him when he picked up their daughter for visits, said her own father died in a coal mine accident when she was a teenager. "It's something you never get over," she said.
It was not immediately clear whether Boni left a suicide note.
Chisolm did not, the sheriff said. Relatives told investigators Chisolm had been depressed about personal matters and drinking heavily in the weeks before his death. Chisolm's obituary also said he had been ill. Members of the Chisolm family did not immediately return telephone messages Tuesday.
Chisolm's brother had visited just before the suicide. As he prepared to leave, Chisolm called out "and more or less said, 'I'll be seeing you,'" the sheriff said.
Chisolm had 11 years of mining experience and had worked at Sago for a year before the accident. Boni had worked as a coal miner for 36 years and had been at Sago for more than a year.
On the morning of the blast, Boni was not in charge of safety; rather, he was restarting a water pump in the mine. He escaped with co-worker Ron Grall and the rest of their crew. Boni and Grall spoke a few weeks later.
"He said he just had enough of it," Grall said Tuesday. "The job wasn't stressful. It was just the way the investigators treated him. They treated me the same way. They acted like it was our fault, like we did it.
"The way I look at it, it wasn't nobody's fault," he said. "It was one of those freaks of nature that hardly ever happens. It probably happens once in a hundred years, and it may never happen again."
ICG provided grief counseling to Sago employees after the accident and has since renewed the offer.