But the plan went horribly awry when a vast amount of natural gas had built up in the home before something set inside a microwave oven ignited the blaze.Leonard died around 9:15 a.m. Tuesday at an Indianapolis hospital, according to an Indiana Department of Correction spokesman. The Richmond, Indiana, explosion was a double explosion which occurred at 1:47 PM EST on Saturday, April 6, 1968, in downtown Richmond, Indiana. One year of his sentences was suspended, and the rest was to be split between jail and work release.That hit man was later revealed to be an agent with the Bureau of Alcohol, Tobacco, Firearms and Explosives.Leonard’s death doesn’t change the fact that Jennifer and Dion died, Buxton said. “And that, I’m sure, will never change.”In 2017, Leonard was convicted and received an additional 50-year sentence in a murder-for-hire scheme authorities say he concocted from jail after his arrest.“The motivation here is greed,” Marnocha said. AD Mark Leonard, the man considered the mastermind behind the 2012 Richmond Hill neighborhood explosion that killed two people and wounded at least a dozen others, is dead. Talk:Richmond Hill explosion Jump to ... WikiProject United States / Indiana (Rated Low-importance) This article is within the scope of WikiProject United States, a collaborative effort to improve the coverage of topics relating to the United States of America on Wikipedia. Two people unaccounted for pic.twitter.com/fa13ohNnIu At about 11:10 p.m., on November 10, 2012, a large explosion occurred in Richmond Hill, a subdivision on the southeast side of Indianapolis. Officials did not release further information regarding his death.Robert Leonard, who was convicted of murder and multiple felonies, was sentenced to life without parole.Leonard was at the Wabash Valley Correctional Facility in Sullivan County serving two life sentences for his role in the explosion that rocked the southeast-side neighborhood that destroyed five homes and damaged more than 80 others.Gary Thompson pleaded guilty to charges of conspiracy to commit arson and received a 30-year sentence, with 10 years suspended.Leonard was being held at the Wabash Valley Correctional Facility but was transferred to the hospital several days ago.Mark Leonard was convicted in 2015 of two counts of murder as well as a litany of other charges, including multiple counts of arson and conspiracy to commit arson. “And I think when the motivation is that, what we have is a person ... who is the worst of the worst.”Glenn Hults, a friend of Leonard's who said he knew about the plot beforehand but didn't call police, was sentenced to three years. The Ontario County Sheriff's Office confirms it removed two bodies from inside a Richmond house that exploded early Tuesday morning. We want to hear from you.Chaos ensued and two people died as the flames spread quickly through the neighborhood.Sign up for free newsletters and get more CNBC delivered to your inboxGet this delivered to your inbox, and more info about our products and services.