ROUND ROCK, Texas (KXAN) — An 11-vehicle crash that included an 18-wheeler closed a portion of eastbound State Highway 45 Tuesday morning in Round Rock, police say.

The 18-wheeler that was part of the crash rolled over and spilled diesel across the highway, and police say tow trucks are on the scene to remove all the inoperable vehicles. A hazmat crew is also there to clean up the diesel fuel, and SH 45 is closed between A.W. Grimes Boulevard and Interstate 35.

Round Rock officials said an investigation into the cause of the crash is ongoing, but confirmed the Texas Department of Transportation had de-icing trucks on scene. Freezing fog blanketed the area this morning, especially north of Austin, which could have made roads slick Tuesday morning.

Police initially tweeted about the crash at 7:45 a.m.

As of 12:20 p.m., one lane of the highway is open while hazmat crews continue to clean up the diesel spill, police say.