(NBC News) — Tonight on a two-hour “Dateline,” the Moore and Ayala families worked together for years on a multimillion-dollar farm until manager Roberto Ayala was killed in an explosion. As police investigate family members start to turn on each other.

Keith Morrison reports on this murder mystery, entitled, “Family Business.”  The episode includes interviews with Roberto’s son Fabian Ayala, Roberto’s brother Eduardo Ayala, ATF agent Brian Parker and more.

Here’s a preview of Morrison’s investigation:

They live modestly here in California’s Central Valley, multi-millionaires in crop dusters and battered pickup trucks. Deeply conservative, self-reliant, tough enough to thrive in a dangerous business that takes guts and brains. And, too often,  lives.

Here, among the churning, slashing machinery, the high voltage power, that helps grow the food of life, death can take a man unawares.

Even on a sleepy summer day.

BRANDY HAVENS: We just looked up and there he was.

Like the day a little boy burst from the field of sunflowers next to Brandy Haven’s place.

BRANDY HAVENS: He was beet-red, sweaty.  He– just covered in mud, head to toe.  He had his tennis shoes in his hands.

KEITH MORRISON: Carrying his shoes?

BRANDY HAVENS: Carrying his shoes.

KEITH MORRISON: You mean he’d been running barefoot?

BRANDY HAVENS: He said he’d took ’em off.  I– I think that he got stuck in the mud, in the sunflowers.

Brandy and her kids live in a rambling farmhouse next to one of those big farms in Colusa County.

Idyllic life out here, quiet, predictable.  Until the Saturday afternoon that little boy appeared, like magic, from the sunflower field.  Couldn’t have been more than 7-years-old or so.

KEITH MORRISON: S– so what’d he say?

BRANDY HAVENS: He said that his dad was on fire and he needed to call for help.

On fire? How could that be?

Watch “Dateline” tonight on  NBC4  at 9 p.m.