Plane Crashes on San Diego Freeway : Near disaster: Two in single-engine Cessna hurt, but no one injured on the ground. Power lines hit in afternoon mishap; freeway traffic jammed.

A single-engine plane en route to Van Nuys Airport lost power and crashed onto the San Diego Freeway in Sepulveda Friday afternoon, injuring the pilot and a passenger, cutting electrical power to central Van Nuys and snarling rush-hour traffic for miles.

The California Highway Patrol closed all southbound lanes for an hour, backing up traffic for five miles to the north, beyond the Simi Valley Freeway, Officer John Escobedo said. Drivers slowing to gawk from the northbound lanes caused a jam that stretched five miles to the south, he said. Traffic came almost to a halt on surrounding city streets inundated by motorists leaving the freeway, Los Angeles police said.

CHP Officer Cleo Green said it was “chaotic” for a time as northbound San Diego Freeway traffic backed up all the way to the Santa Monica Freeway and the ripple effect spread to the Foothill, Ventura and Hollywood freeways.

In an attempt to get off the gridlocked San Diego Freeway, some motorists turned their vehicles around, traveling the wrong way off “on” ramps, Green said.

No vehicles were hit by the plane and no one on the ground was injured, authorities said.

The plane crashed upside-down on the southbound side of the freeway just south of Roscoe Boulevard, about a mile east of the airport.

The pilot of the Cessna 177, whose name was withheld until relatives could be contacted, was in serious but stable condition at Holy Cross Medical Center in Mission Hills with head injuries, hospital nursing supervisor Carol Mears said.

Passenger William A. Ryan, 50, of Los Angeles, was in good condition with a broken left arm, Mears said. Both men were taken to the hospital in a Fire Department helicopter.

The pilot radioed the Van Nuys Airport control tower moments before the 3 p.m. crash to report engine trouble, airport spokesman Bob Hayes said. The pilot radioed again to report power failure, said Los Angeles city Fire Department Capt. J. B. Benoit, who was on the phone with the tower discussing emergency preparations for the landing when the pilot’s second call came in.

The plane was based at Van Nuys Airport and registered to Ryan, Hayes said. It was not determined whether the plane had taken off from Van Nuys or was arriving from another airport, Benoit said.

The plane snagged two sets of high-voltage lines that cross the freeway at Roscoe Boulevard and cartwheeled to the pavement, witnesses said. The downed lines resulted in power failure to 16,000 customers in a four-square-mile area, including the Van Nuys courthouse and the Los Angeles Police Department’s Van Nuys station, said Department of Water and Power spokesman Ed Freudenberg.

Power was restored to all but 800 customers within an hour, he said, and the DWP expected to have all power restored by late Friday night.

“He was coming in, trying to land,” said Joseph Diterlizzi, who was on his way home to Van Nuys when the plane crashed several feet in front of his car. “He hit the wires, which flipped him.”

“When he hit the concrete, he was about three feet behind me,” said witness Steve McOwen, who was on his way home after picking up his two sons from school in Mission Hills. “We asked the passenger if he was OK, and he said, ‘I’m fine. My head and my arm hurt.”’

The pilot was “breathing loudly and waving his hands around when we asked him questions,” McOwen said. He said he was first alerted to the plane by his sons, who saw it through the rear window of the car and said its propeller was not rotating.

Burbank resident Larry Anderson, a flight instructor who was en route from Van Nuys Airport to Burbank Airport, said the plane looked as if the pilot was trying to fly under the power lines, but clipped them. Anderson, who flies Cessna 177s as an instructor, said the pilot appeared to have sufficient speed and altitude to go over the power lines.

The Highway Patrol reopened the two right southbound lanes about 4 p.m., and all lanes were reopened after the plane was removed about 4:50 p.m., Escobedo said.

“You wouldn’t think traffic could get any worse, but it did,” CHP Sgt. Richard Sirovy said.

Times staff writer Mike Connelly contributed to this story.