Former Massey Energy Chief Executive Don Blankenship was sentenced to a year in prison and fined $250,000 Wednesday for his role in a 2010 coal mine explosion that killed 29 people.

Blankenship, known as West Virginia's "king of coal" for his rags-to-riches background and tough approach to business, was also sentenced in U.S. District Court to a year of supervised probation after release.

A jury found him guilty in December of conspiring to violate safety standards at the Upper Big Branch mine, the site of the blast.

The jury found Blankenship, 66, not guilty of making false statements and of securities fraud. The jury had deliberated more than two weeks and had twice told Judge Irene Berger it was deadlocked.

Blankenship, who headed Massey 2000-10, had been accused of conspiring to falsify dust samples and violating federal securities laws by lying about company safety practices.

Relatives of those killed and prosecutors hailed the decision as sending a message on mine safety in coal-rich West Virginia.

Berger moved the trial from Beckley, near the site of the mine, after Blankenship's lawyers complained he could not get a fair trial there because of intense pretrial publicity.

The death toll at Upper Big Branch, about 40 miles (65 km) south of Charleston, was the highest in a U.S. mine accident since 91 miners were killed in a 1972 fire at an Idaho silver mine.

Massey Energy was bought in 2011 by Alpha Natural Resources Inc. for about $7 billion.