At least 10 people lost their lives on Oklahoma highways over the long Memorial Day holiday weekend, authorities said.
The latest deaths occurred just before 6 p.m. in Grady County, the Oklahoma Highway Patrol said.
A pickup truck went through a stop sign that was obscured by a tree and collided with a pickup truck driven by Jacy Poston, 17, troopers said.
Jacy Poston was pinned under the truck and Jimmy Poston, 56, was under the trailer after the impact threw them from the vehicle, troopers said.
Both suffered massive head injuries and were pronounced dead at the scene of the accident on a Grady County road, troopers said. It wasn't immediately known how the Postons were related.
The driver of the other vehicle, 43-year-old Cheryl Bell of Justin, Texas, suffered a broken arm and was treated and released from a Duncan hospital, troopers said.
In an accident about 7:38 a.m. Monday, Rusty Andrew Stephens suffered massive injuries when his pickup truck crossed the center line of U.S. 270 and collided head-on with another truck near Haileyville, the patrol said.
Stephens, 22, of Hartshorne was pinned four about 22 minutes and died at a McAlester hospital.
The driver of the other truck, 67-year-old Carl Crabtree of McAlester, wasn't hurt.
On Saturday, a 19-year-old Hennessey man was killed in a weather-related accident in Canadian County, troopers said.
Mark Moreno Lopez died about 10:15 p.m. Saturday when his pickup truck ran into two horses in the middle of State Highway 3 near Piedmont, the patrol said.
After striking the horses, Lopez's truck lost control, ran off the road and struck a building. He died at the University of Oklahoma Medical Center in Oklahoma City.
Also killed Saturday was a Broken Bow man, whose pickup collided with another truck on U.S. 259 in McCurtain County, the patrol said.
Steven Story, 44, suffered internal injuries and was pronounced dead at the scene of the accident.
His passenger, Kelly Mundell, was treated for minor injuries and released from McCurtain Memorial Hospital in Idabel, the patrol said. The driver of the other truck, Lyndell Dale Pratt, wasn't hurt.
Story's truck hit Pratt's vehicle when Story tried to pass Pratt as Pratt was trying to make a left turn, the patrol said.
The impact caused Story's truck to roll two times and come to rest in a ditch. Story was thrown from the wreckage.
Others killed include:
_ 27-year-old Anthony Crook of Catoosa, whose car failed to follow a curve on a Tulsa County road Monday morning, ran off and hit a tree. The car caught fire and burned.
_ 41-year-old Ronald James Ballou late Friday after his motorcycle was struck from behind as he was stopped behind a car that was waiting to make a left turn on Oklahoma Highway 82 near Tahlequah.
_ 51-year-old Michael E. Hollaway of Arkadelphia, Ark., who was driving his motorcycle east on Interstate 44 in Tulsa about 5 p.m. Friday when he struck the rear of a car, the patrol said.
_ 61-year-old Earl Dean Dennett of Enid, who suffered massive injuries when his vehicle left U.S. 81 near Kingfisher and rolled 1 1/2 after sliding off the highway about 7:30 p.m. Thursday.
_ an unidentified South African man who was killed Saturday night near Alva when he lost control of the wheat truck he was driving on a curve on a hill, causing the truck to slide, the wheat to shift and the truck to roll. His name wasn't immediately released.