An early morning collision on Highway 165 in Hilmar between a school bus and a semi truck left one man dead and one woman with moderate injuries Thursday, the California Highway Patrol reported.

The driver of the semi truck, identified as 33-year-old Matthew Melvin Selby of Chowchilla died at the scene of the collision.

The driver of the school bus for the Hilmar Unified School District was identified as Roxanne Boeken, 57. Boeken sustained moderate injuries to her legs in the collision and was flown by air ambulance to Memorial Medical Center in Modesto, according to the CHP.

The bus was not transporting children at the time of the collision.

The semi truck was hauling 14 cattle and at least four cattle were killed in the crash, the CHP reported.

The collision was reported just before 6:30 a.m. on Highway 165, near Turner Avenue and south of downtown Hilmar.

Boeken was driving the bus southbound on Highway 165 at an unknown speed and the semi truck was headed northbound on the highway. For an unknown reason, Selby turned the semi, directly into the path of the oncoming bus. Boeken attempted to swerve out of the semi truck’s way, but was unable to avoid it and the two vehicles collided head-on, according to the CHP.

Selby was not wearing a seat belt, the CHP reported

Highway 165 was closed to traffic during the investigation, causing some delays, the CHP reported.

The investigation into the collision is ongoing. The CHP stated that at this time it is unknown if drugs or alcohol played a role in collision.