A truck driver faces with two counts of first-degree manslaughter, more than three months after a boulder tumbled from a truck he was driving and smashed into a car, killing two elderly women.

The incident occurred in late March in Pauls Valley, Oklahoma.

A 65-year-old woman was traveling southbound on US-77 when the boulder crashed through the windshield of her car. Two passengers – sisters who were ages 83 and 89 – were killed instantly.

An Oklahoma Highway Patrol officer said the boulder fell from a semi-truck that was heading north. The officer described the boulder as the size of a basketball and said it weighed 40 to 50 pounds.

The driver of the truck didn’t stop at the scene of the crash. In fact, the driver said he didn’t realize a crash occurred once officials located him. He entered a not guilty plea to the manslaughter charges.

He has pleaded not guilty to the charges.

One law enforcement official from the Oklahoma Highway Patrol traffic/homicide unit said the tragic deaths could have been prevented.

“Before you get on the highway, if you’re loading/unloading any type of things that would be dangerous, to make sure your truck, your equipment, everything like that, is secure before you travel on the road,” he said.

Dangers exist every day on the road, but by charging this man with manslaughter, authorities clearly have determined this danger could have been avoided and that this driver was negligent and should be held accountable in the women’s deaths.

If you ever are injured because of the negligence of another, or if you lose a loved one as the relatives of these two sisters did, an attorney can inform you of your rights.