Authorities are still investigating a Thousand Oaks highway crash that killed a Huntington Beach man.

On March 17, Christopher Smith, 45, was driving a 1999 Ford Crown Victoria south on the 23 Freeway when his car went straight as the road curved near the northbound transition to the 101 Freeway. It was 10:38 p.m. when his car traveled 750 feet through a bumpy dirt/grass field before it went off a 20-foot ledge and landed on the 101, California Highway Patrol Officer Randy Pickens said.

According to the CHP, witnesses reported the car was airborne before it went onto the freeway and landed at an angle perpendicular to the road.

"We don't know where he was going or why he went straight when the road curved," Pickens said.

Neither alcohol nor drugs is suspected to be a cause, but toxicology tests are being run, the officer said.

Newbury Park resident Dwight Fujii, 52, was driving a 2006 Ford F-150 pickup truck north on the 101 Freeway when Smith's car appeared in his path.

Fujii's pickup truck struck the side of Smith's car, spun out of control, overturned and came to rest on its wheels, a CHP report said. Both vehicles ended up facing southbound on the northbound roadway.

Smith was pronounced dead at 11:28 p.m. at Los Robles Hospital and Medical Center.

The cause of his death was multiple blunt force injuries, Ventura County senior deputy medical examiner Armando Chavez said.

Fujii was taken to St. John's Pleasant Valley Hospital in Camarillo, where he was treated for a sprained ankle.

—Nancy Needham