INDIANAPOLIS — It was on the night of Nov. 10, 2012, just a little after 11, when the south side community of Richmond Hill was rocked by an explosion that some neighbors at first thought was as the result of a plane crash.

John Longworth recalls what he was told by a fire department chaplain hours after he arrived in the vicinity of his son’s house on Fieldfare Way and failed to make contact with Dion and his wife, Jennifer, who were at home that night.

”’Well, 8340 was at the epicenter of the blast, and we do believe there is at least one body there.’”

Jennifer, a Greenwood elementary school teacher, died in the collapse of the two-story home after the house next door blew up.

Dion, an audio electrical engineer, survived for a while in the basement as responding Indianapolis firefighters from just a couple blocks away struggled to save his life from advancing flames fed by natural gas.

”I know that the firefighters suffered because I know initially they felt like they had a chance to save him, and then they couldn’t and felt really awful about it,” said the still-grieving father.

Within hours, the owner of the home on the neighboring lot, Monserrate Shirley, returned to Richmond Hill along with her boyfriend, Mark Leonard.

The couple had been at a southeast Indiana Casino when they received word of the tragedy.

It didn’t take investigators long to determine that Leonard had a history of insurance fraud and that the blast at Shirley’s house was set by an altered gas meter that fed natural gas into the house that was then set off by the explosion of a metal canister inside a microwave oven in the kitchen.

”Before the funeral was held, we had figured out that the probability is that somebody did this,” said John. “Somebody caused this to happen.”

Leonard hatched a scheme to defraud Shirley’s home insurance carrier out of a $300,000 pay-off.

”I didn’t get the impression that he was capable of deep thought,” said John, who attended Leonard’s trial in South Bend, “because if he had, he would see, Moncie is in debt for over $300,000, and her insurance is $300,000, that’s less than zero. She would still be in debt. But he thought he could somehow get the money before she got it and leave her in debt so he was that much of a conniver.”

Leonard and his brother, Robert, who was accused of setting the timer on the microwave oven the day of the blast, were arrested the week before Christmas and charged with felony murder.

Financial losses in Richmond Hill were pegged at $4,000,000 as 90 homes were damaged.

”If I would have happened to have run into Mark Leonard, he would have been dead before they arrested him. That’s where I was,” said John. ”It wasn’t just me. There were people in the neighborhood that wanted to kill him.”

The Leonard brothers were convicted in separate trials in 2015 and sentenced to life in prison without parole.

Shirley pleaded guilty to conspiracy to commit arson and was sentenced to 50 years in prison. She’s eligible for parole in 2036.

This week’s date and seeing justice done reminds John of how much he’s lost to the greed of his son’s neighbors.

”Every year this time it really comes back to me,” he said. ”For myself, I don’t care anymore.”

And that includes for the fate of the man who put the entire murderous plot in motion and died of a lingering blood disorder in 2019, six years after he blew up his girlfriend’s house.

”Mark Leonard, he had almost died the previous spring from the disease that eventually killed him,” recalled John. “If he would’ve died then, that wouldn’t have happened.”

John said state legislators eventually passed a law requiring the installation of excess flow valves in new and retrofitted homes to cut off the free flow of gas into a home due to sabotage, accident or malfunction.

John said if such a device would have been installed in his son’s house, Dion might have survived the fire that took his life before firefighters could carry out a rescue.