Freeway Crash Kills Motorcyclist : Accident: Wreck stalls traffic on Interstate 5 for two hours. Another one stops up things at Orange and Riverside freeways.

Motorcycle accidents an hour apart on two Orange County freeways left one man dead and another seriously injured Sunday, snarling end-of the-week traffic for thousands of drivers for hours, authorities said.

Killed on Interstate 5 in Tustin was a 22-year-old Marine based at El Toro, authorities said. His identity was withheld pending notification of family.

He was run over by a big rig in a crash that involved four vehicles, officials said. It began when when the Marine, driving at “a high rate of speed,” moved from the northbound Interstate 5 to the Costa Mesa Freeway and tried to pass a blue Volvo in the slow lane, California Highway Patrol officials said.

The motorcycle collided with the left rear of the Volvo, throwing the cyclist into the middle of the freeway. The driver of a big rig then swerved to avoid the driver but couldn’t, running over him, authorities said.

“His body went underneath the right rear dual (tires) of the big rig,” said CHP Sgt. Virgil Hartz.

Meanwhile, the victim’s runaway Yamaha collided with the left front tire of a motor home.

Hartz said of the cyclist, “It was basically his errant judgment that caused the accident.”

That 4:10 p.m. accident forced the closure of three of the five lanes and, with traffic on Interstate 5 already slowed by construction, brought drivers to a near-halt for miles, all the way back to Irvine, authorities said.

It took patrol crews and coroner’s officials nearly two hours to clear the scene and get traffic moving again.

“It was stop-and-go, backed up down to Sand Canyon, Jeffrey (exits), probably five miles or so,” Hartz said. “But people seemed to be handling it pretty well.”

About an hour earlier, around 3:15 p.m., another motorcycle accident--this one involving only the one vehicle--slowed traffic at the intersection of the Orange and Riverside freeways. The cyclist was taken to Anaheim Memorial Hospital with injuries, but his condition was not immediately known.

No other details were available Sunday evening on the Anaheim accident.