RAMONA, Calif. — A pickup truck driver died Friday following a crash with a school bus in Ramona, authorities said.

Shortly after 4 p.m., a man was driving a Chevrolet 2500 southbound on Mussey Grade Road near Foster Truck Trail when a Ramona Unified School District bus carrying two children was headed northbound, California Highway Patrol said in a news release.

While taking a left-hand curve, the 56-year-old truck driver lost control of his vehicle and entered the northbound lane, CHP said. The truck drove into the path of the oncoming school bus, resulting in a head-on crash.

The truck went partially up a small dirt embankment before going back eastbound across both lanes of Mussey Grade Road, CHP said. The truck then came to a stop, trapping the driver inside.

Medics airlifted the driver to Palomar Hospital in Escondido, where he died.

The 48-year-old bus driver was also taken to Palomar Hospital to be treated for minor injuries. The two children were not injured.

Investigators did not yet know if alcohol or drugs were a factor in the crash.