STROUD, Oklahoma - The Oklahoma Highway Patrol is investigating the cause of a deadly crash on the Turner Turnpike east of Stroud early Wednesday.

They say a semi and construction vehicle collided in a construction zone just before 12:45 a.m. near the toll plaza. The construction vehicle made an improper U-turn in front of the semi truck, according to traffic investigators.

The OHP says a passenger in the construction vehicle was killed. Both drivers were taken to the hospital. OHP says they are expected to be OK.

Troopers said it's an unfortunate reminder to keep safety in mind - especially in a work zone.

"You've got to remember traffic out here is traveling at 75 mph, and driver isn't expecting a vehicle to come across the road," said Lieutenant Kera Philippi, OHP.

Traffic investigators worked the scene for several hours before lanes were reopened. They waited for daylight as they used a drone in their investigation.