The California Highway Patrol (CHP) says that a fatal chain-reaction crash that occurred early Wednesday was sparked by a trucker trying to do a good deed.

The incident began around 1 a.m. on April 21 on northbound I-5 south of Westley, California, when a semi truck driver noticed a red sedan swerving across both lanes of the interstate.

The truck driver “felt the motorist’s driving behavior was so extreme they felt obligated to stop it. The big rig driver actually boxed in the DUI driver … (He) used his trailer in a manner to stop the DUI driver from proceeding,” said CHP Officer Tom Olsen.

Two other trucks came to a complete stop behind the suspected DUI driver and the truck boxing it in.

A fourth semi driven by 41 year old California resident Elpidio Ramirez Tovar failed to stop, rear-ending the truck in front of him and pushing that truck into another truck. “His cab was completely ripped off the trailer so he was probably going freeway speeds at the time of the impact or pretty close,” Olsen said.

CHP says that Tovar was ejected onto the shoulder of the roadway and that he was pronounced dead at the scene.

CHP arrested 40 year old motorist Daniel Avilan-Tirado on DUI charges.

CHP says that there is no indication that the truck driver called 911 prior to boxing in the motorist.

“The intentions were good, but we’d rather somebody contact 911. That would be the safest option for all of us,” Olsen told Fox40.

It isn’t clear whether the truck driver who boxed in the motorist will face charges. The investigation is ongoing.