STOCKTON (CBS13) – A big rig driver was killed in an early morning crash involving two big rigs and a silage truck near Stockton on Tuesday.

The incident happened along northbound Highway 99 south of Arch Road.

California Highway Patrol says a Peterbilt silage truck was on the right shoulder of the freeway after being disabled. Two other big rigs, another Peterbilt and an International, started approaching.

The second Peterbilt started moving over a lane to give some space to the disabled truck. However, for some reason the International wasn’t able to slow down and instead rear-ended the Peterbilt.

The crash sent the International right into the silage truck on the shoulder.

The International driver was killed in the crash, CHP says.

Officers are still investigating if drugs or alcohol contributed to the crash.

Lanes on northbound Highway 99 were closed for most of the morning after the crash. They have since reopened.