Back-to-Back Accidents Jam Freeway for Hours : Traffic: Early morning truck crash, then car fire, snarl San Diego Freeway traffic into the early afternoon.

A pair of consecutive SigAlerts at virtually the same spot on the San Diego Freeway resulted in a traffic nightmare Friday, snarling northbound traffic for nearly eight hours, authorities said.

In the first accident, the driver of a grocery truck lost control of his big rig just before the morning rush hour and ran off the freeway. The driver escaped with only minor injuries, but the accident jammed the freeway throughout the morning.

Traffic woes for northbound commuters increased when a car caught fire just as the truck was being cleared away and the freeway was about to be fully reopened at 1 p.m., California Highway Patrol Officer Lyle Whitten said.

“We had to issue another SigAlert,” Whitten said. “You get one thing taken care of and another thing starts.”

The afternoon SigAlert, which closed one lane, lasted another 45 minutes. The car fire was not believed connected to the morning incident, which lasted about seven hours and backed up morning and noontime traffic for more than 5 miles.

Whitten said the trouble started about 5:30 a.m., when trucker Percy Atkins, 49, of Diamond Bar lost control of his tractor-trailer north of the Magnolia Street exit.

The rig hit a concrete barrier that was set up to protect a construction area, then struck several yellow plastic safety barrels, splattering sand and plastic foam over a wide area of the freeway, Whitten said. The truck, which was empty, flipped off the freeway and became airborne for about 40 feet before landing in a culvert 20 feet below the freeway.

“It landed flat as a pancake,” Whitten said. The rig’s cab was crushed, but Atkins, who was wearing a seat belt, walked away.

“It’s a miracle the man even survived, much less having minor injuries,” Whitten said. “It just wasn’t his time to go.”

Atkins, who was taken to UCI Medical Center in Orange for treatment of the injuries, later told police that his right front tire blew out, forcing the truck out of control. No other cars were involved.

In the second incident, police said a rented car caught fire in the engine compartment and was destroyed. There were no injuries, and the car’s driver was not identified.

That accident also occurred just north of the Magnolia Street exit, further snarling traffic until police could clear the vehicle from the scene.