OKMULGEE COUNTY, Oklahoma - Two Oklahoma Department of Transportation workers were taken to the hospital after a crash involving a semi.

Around 9:30 Tuesday morning, an ODOT crew was on a sign repair job on Highway 75 just north of Highway 16 in Okmulgee County, according to the Oklahoma Highway Patrol.

The OHP says the two ODOT workers were in a flatbed truck when it was hit by a semi hauling a load of steel beams. The impact ejected both ODOT workers, the OHP says.

The OHP report identifies the driver of the ODOT truck as Brian Fuller, 45. The OHP says his co-worker was Sean Birnie, 19. Paramedics took both men to a Tulsa hospital, Birnie in an ambulance and Fuller in a helicopter.

The driver of the semi, 52-year-old Richard Ganzer, refused treatment at the scene, according to the OHP. 

Troopers say they're still investigating the cause of the crash.