On a sunny April day in 2004, 4-year-old Justin Simmons played on the stairs to Orvil and Roberta Reedy's porch. Orvil had brought out his riding lawn mower to cut the grass for the first time that year. Roberta, a licensed day care provider, ducked inside her door to change the diaper of Justin's baby brother, Josh.

Moments later, according to court statements, as Orvil Reedy rolled backward on a slope, he felt a bump, and the mower stalled. He tried to restart it, then saw Justin's legs sticking out from underneath, and screamed.

On Wednesday, two years after Justin's terrible death, a courtroom battle began to decide who, if anyone, should be held liable: the Reedys, or the company that made the mower?

Ron and Kristie Simmons, Justin's parents, have sued the Reedys and MTD Products Corp., the world's largest lawn mower manufacturer, for $6 million. The Simmonses' attorney, Brent Brown, focused heavily on MTD in his opening statement in Roanoke Circuit Court, arguing that the company failed to meet safety standards and failed to address known dangers in its design.

Lawyers for MTD and the Reedys sat at the same defense table but pointed fingers at each others' clients as the trial proceeded.

MTD attorney John Fitzpatrick said his company has been a pioneer in riding mower safety, and the accident never would have happened if Orvil Reedy had read the owner's manual and safety warnings.

"For a failure to use common sense, we are being sued," Fitzpatrick said.

John L. Cooley, the Reedys' counsel, said that nothing the Reedys did that day was unreasonable enough to be considered negligence.

The morning of April 22, 2004, seven days after Justin turned 4, Kristie Simmons dropped her children off at the Reedys' house in Daleville. The Simmonses had used the Reedys' day care since Justin was an infant.

According to court statements, Roberta Reedy was inside her house for only a short period of time while Justin was outside unsupervised.

Orvil Reedy had seen Justin heading toward the house, and thought he was going inside, Cooley said.

As he mowed uphill, the mower's gears slipped. He depressed the clutch, and as the mower rolled backward, he hit Justin, Cooley said.

No criminal charges were filed against the Reedys. Roberta Reedy surrendered her state day care license following a Department of Social Services investigation.

Eight jurors watched as Brown spent more than an hour detailing the working of the lawn mower and what he said were flaws in its design that directly contributed to Justin's death.

"A job half done is a job undone," Brown said, referring to MTD's obligation to protect children from such accidents.

MTD, based in Cleveland, Ohio, makes mowers for Sears, Home Depot and Lowe's, with such brands under its umbrella as Yard-Man and McCulloch.

The Reedys' mower was manufactured in 1988. Orvil Reedy had used it since 2002, after acquiring it from a neighbor and having it fixed up.

Brown argued that although the mower's blades don't turn when it's in reverse gear, MTD neglected to design the mower so that the blades don't turn when the mower is rolling backward on an incline. Depressing the clutch while rolling backward allows the blades to keep spinning, which is what happened when Reedy rolled downhill.

Fitzpatrick countered that no mower exists that has a device that prevents its blades from spinning when it inadvertently rolls backward.

If operators depress the clutch to keep the blade spinning while going backwards, they're violating the instructions in the owner's manual and safety warnings on the mower, he said.

The trial is scheduled to continue through Friday.