Two drivers were killed when they lost control, crossed into opposing traffic and slammed into a tractor trailer.
They happened on Highway 221 Near Prosser. Troopers say they're now increasing patrols and asking drivers to be more alert.
"You need to really focus, when you're driving down the road, to stay on your side of the road, to the left of that center line. Because once you cross that center line it can just happen in seconds," said Officer Terry Leibrecht.
Wanita Brown works near the highway. Her boyfriend drives a truck for a living. She says he uses the highway regularly and claims it's hard for big rigs to stop quickly in an emergency.
In comparison to a route that has a lot of twists and turns, State Police say Highway 221 is almost entirely flat, which they say may lead to too many drivers becoming too comfortable for their own good."
"You don't have a lot of cross traffic coming upon you. You don't have really a lot to look at. So, a person could get kind of lulled into not paying attention to where the center lines are at or where the fog lines are at," Liebrecht said.
This is the 12th fatal accident involving commercial trucks in the state this year. Investigators put the truck driver at fault in only two of those cases. Liebrecht says the increase of wineries and dairies near Highway 221 brings more drivers going to and from work.
"Early mornings, people get tired or they just came off work and it can do a lot of damage to you when you're tired and not paying attention," Wanita said.
Troopers say this was never a spot they considered dangerous before, until now.