Buildings Continue Their Slide

Los Angeles County safety experts Thursday scrambled to determine what is causing the major landslide that has undermined a hilltop office park in the aptly named South Bay community of Rolling Hills Estates.

Workers from 18 small businesses evacuated two buildings Wednesday afternoon as the walls began to warp, windows cracked under pressure and sidewalks outside buckled. The buildings were temporarily condemned by county firefighters, and a third was closed to everyone but tenants. No one has been injured.

As engineers studied the foundations and soil under the structure, they expressed concern that parts of the office complex could collapse and topple into a parking lot below. The two buildings at the edge of the office park, which overlooks a lush green canyon and retail shopping district on Silver Spur Road, sunk as much as six inches overnight, and a hillside along a walkway in front of one building had slipped by nearly a foot, Los Angeles County Fire Department Inspector Henry Rodriguez said.

By Thursday afternoon, a stairwell leading up to the second story of one building had shifted so much that it had to be closed, a retaining wall under the building had slanted to a 50-degree angle, and firefighters cordoned off the parking lot. Rodriguez said that many tenants in the building reported suffering from vertigo Wednesday, but hadn’t realized that it was because the building was moving.

“The ground has been slipping pretty steadily,” Rodriguez said.

The office park, built in 1981, has a clean safety record, said John Kelly, superintendent of building for the Los Angeles County Department of Public Works.

“They’ve had some cracking and displacement over the years that they’ve repaired,” Kelly said. “The most likely cause of this is nature behaving as nature does.”

Engineers speculated that the soil under the complex could have become unstable as a result of heavy rains over the past month. An underground water main next to one of the buildings broke three weeks ago, but was quickly repaired, county officials said.

“We don’t have any evidence” that the water main leak led to the landslide, Kelley said. But as a precaution, work crews cut off all utilities to the two heavily damaged buildings.

Private engineers inspected the foundation of one of the buildings two weeks ago and noticed that it appeared to be settling, said Ray Quigley, business manager of QBM Partnership, which owns the complex. The company had asked geotectonic specialists to study the problem, but they had not reported back by the time the landslide forced tenants to evacuate, Quigley said.

Construction workers shored up the underpinnings of one of the two unstable buildings within the last few years, Quigley said, but he could not remember when.

The incident was only the most recent in a costly series of landslides on the Palos Verdes Peninsula, where, over the years, shifting earth has destroyed homes and businesses in areas including Portuguese Bend and Rancho Palos Verdes.

Most tenants in the office complex were allowed to grab a few belongings Wednesday night, and firefighters helped a few others move out Thursday. County safety officials said they would block off the office park overnight to prevent any tenants from trying to retrieve office equipment or furniture without supervision.

At an Allstate office in the complex, insurance representatives had filled more than 50 boxes with office supplies and managed to get their phone lines forwarded to the Southern California headquarters in Orange so that prospective customers wouldn’t be turned away.

“This is rather devastating,” said agent Steve Nollner, of Rolling Hills Estates, “but it’s nothing compared to Northridge.”