EARTHQUAKE: THE LONG ROAD BACK : 3rd Garage to Be Razed at the Northridge Mall : Rebuilding: Engineers advise shopping center managers to demolish another parking deck.

Managers of the Northridge Fashion Center, one of the hardest-hit public spaces in the Jan. 17 earthquake, have decided to demolish a third parking deck at the four-garage mall at the advice of structural engineers.

The two-level, 1,000-car garage remained standing after the 6.8-magnitude earthquake but suffered enough structural damage to be rendered unsafe and beyond repair, Lloyd Miller, the mall’s general manager, said Wednesday.

The parking garage was built in 1971, when the mall opened, of poured-in-place concrete and is situated off Shirley Avenue between the shopping center’s two Robinson’s-May stores. It was the mall’s largest parking structure, Miller said.

“We just want to make sure everything is safe,” said Miller, who noted that the damage included leaning columns.

Among modern buildings, parking structures “appear to have suffered the largest incidence of partial or total collapse” during the Northridge quake, according to a preliminary report by UC Berkeley’s Earthquake Engineering Research Center.

At least eight public parking structures at popular shopping centers, colleges and hospitals were severely damaged--including two relatively new ones at Northridge Fashion Center and one down the street at Cal State Northridge.

Experts studying the failures have cited building code inadequacies, cost-cutting measures by developers and the earthquake’s unusually high ground accelerations as possible causes. Both CSUN and Northridge Fashion Center are within a mile of the epicenter.

One Northridge Fashion Center garage collapsed completely during the earthquake, trapping a maintenance worker as he drove a mechanical sweeper during his predawn shift. That parking garage, on Shirley Avenue near Nordhoff Street, was erected in 1988-89 of precast concrete, a type of construction that experts consider particularly vulnerable to seismic damage. Its rubble has been removed.

About half of a second garage--farther north on Shirley Avenue near Plummer Street--collapsed and is undergoing demolition, Miller said. It, too, was built in 1988-89 of precast concrete.

“They are so badly damaged, they are unsalvageable,” structural engineer John (Trailer) Martin said of that garage and the newly condemned one.

Asked why so many of the shopping center’s parking structures failed, Miller said, “We are analyzing all of that and it’s hard to say at present but, again, when you’re at the epicenter of an earthquake, things like that can happen.”

The remaining garage at the mall is under review by Martin’s firm, John A. Martin & Associates Inc. of Los Angeles. It is situated off Tampa Avenue near the mall’s collapsed Bullock’s store and, like the newly condemned structure, was built in 1971 of poured-in-place concrete and has been closed since the quake.

Miller said all four parking structures were engineered by the firm of Los Angeles structural engineer Robert Englekirk, who could not be reached for comment Wednesday.