The former CEO of coal company Massey Energy, Don Blankenship, who was convicted in December for his role in a 2010 mine explosion that killed 29 workers, reported to a California federal prison Thursday.

Blankenship, who was sentenced on April 6 to one year in prison for conspiracy to violate safety standards in the wake of the fatal explosion at the Upper Big Branch coal mine in West Virginia, will serve his time at a federal prison facility in Taft, CA.

“Today we saw Don Blankenship go to federal prison where he belongs,” Booth Goodwin, a former US attorney who was part of the case against Blankenship told the Associated Press. “It was a long road, but I am pleased to see him finally start to pay for his criminal conduct.”

On Tuesday, Blankenship’s attorneys attempted to stall his entry into prison by submitting an emergency stay motion that would have kept him free on a $1 million bail as the court considered his appeal. Prosecutors denied the motion, saying that during Blankenship’s appeal process, his legal team had already requested to delay his prison time during his appeal process, ABC News reported.

For background, read Powder & Bulk Solids’ previous coverage of Blankenship’s trial

The West Virginian Record was given a letter from Blankenship, published on Thursday, where the former CEO expressed thanks to his supporters and declared that the “truth” of the incident will emerge. Blankenship asserted that the federal Mine Safety & Health Administration deliberately destroyed documents and hid evidence related to the case.

Blankenship’s letter also stated that the science behind studies that blamed coal dust and worker errors as the causes of the explosion were flawed.

“Science simply disproves MSHA claims that the explosion was propagated by coal dust. Additionally, chemistry tells us that the gas that exited the mine was clearly natural gas from the ground and not coal bed gas from the coal seam,” wrote Blankenship. “All of this is important because it makes clear that contrary to the government’s claims that the coal miners were not doing their jobs, there is no evidence the miners contributed in any way to the explosion.”

Also blaming the media and government generally for misleading statements, Blankenship pledged to continue to expose “the truth about Massey and UBB [Upper Big Branch].”

“The government cannot change the truth, but with the media's help it has thus far covered it up. All we can do is to continue our efforts to uncover it.”