One person died Wednesday evening in an accident involving a semitrailer and a pickup truck in the northbound lanes of Interstate 35.

Diane Terwey, 56, from Hutchinson, Kan., died when the pickup she was riding in collided with a semitrailer carrying an empty flatbed trailer.

Iowa State Patrol Sgt. Bill Hon said the accident happened shortly after 5 p.m.

Dennis Terwey, 63, the driver of the white 2004 Chevy Silverado was taken to Mary Greeley Medical Center, and John David Smith, 37, the driver of the white 1999 Freightliner semi was uninjured.

The passenger side door of the Silverado was pulled off and attached to the cab of the semi, and the semi’s front left wheel was bent under the vehicle. The pickup was turned around, facing the other semi. Clothing and hangers were scattered around both vehicles.

The driver’s side door of the semi had a Walker Tire-Truck & Tow Service logo. The company, based in Odessa, Mo., was not releasing any information regarding the accident.

Hon said little information was available about how the accident occurred.

Hon initially said, after interviewing one witness, that the accident was caused when the semi was attempting to merge on to the interstate.

“It looks like the semi was trying to merge and the pickup was travelling northbound in the right lane and sideswiped the cab of the semi,” Hon said.

According to a preliminary accident report, released about 9 p.m., the semi was travelling northbound on I-35 and the pickup was going southbound. The pickup swerved out of the way of another semi that was changing lanes and crossed into the median, hit the bridge guardrail and crossed into the northbound lanes.

The semi then struck the passenger side of the pickup.

The accident is still under investigation, but the report listed rain as a condition at the time of the accident.

According to the report, the semi received about $25,000 worth of damage and the pickup truck was totalled.

The accident ruptured the fuel tank on the semi, causing diesel fuel to spill onto the interstate. Hon said the Nevada Fire Department controlled the spill by covering it with sand.

Both the Nevada and Ames fire departments responded to the accident and Story County Sheriff’s Office and the Ames Police Department assisted at the scene.

Northbound lanes on Interstate 35 were closed at the U.S. Highway 30 west exit, and traffic was backed up on the interstate and Highway 30, where the traffic was being rerouted.