Quake Damage to 46 Buildings Severe : Disaster: Residential structures left uninhabitable, Red Cross says. Severity of temblor is downgraded to 5.8.

Forty-six homes and apartment buildings were left uninhabitable by the strong earthquake that jolted San Gabriel Mountain foothill cities last week, authorities said Monday.

Teams of building inspectors searched for dangerous structures while American Red Cross volunteers opened centers to help residents begin rebuilding and, in some cases, overcome psychological crises.

Seismologists at the California Institute of Technology downgraded the magnitude of Friday’s 7:43 a.m. temblor from a preliminary reading of 6.0 to 5.8, based on more precise measurements.

They also said the number of aftershocks was surprisingly small. Sixty-four were recorded by midmorning Monday, only 14 of them larger than magnitude 2. The chance of an aftershock measuring 5 or more was only 4% for the rest of the week, said Lucile Jones of the U.S. Geological Survey.

A total on quake damage and the cost of repairs was more elusive.

“We’re receiving many calls for inspections,” said Don Nollar, director of Pasadena’s Planning and Building Department.

Pasadena and its neighbors at the head of the San Gabriel Valley, the small cities of Sierra Madre and Monrovia, bore the brunt of damage.

An American Red Cross tally of the area’s residential damage found 23 single-family homes and 23 apartment buildings damaged badly enough to be uninhabitable, said Robin McCarthy, spokeswoman for the Red Cross.

In addition, 241 single-family homes and 27 apartment buildings had less serious damage, she said.

McCarthy said the agency did not have a dollar estimate of the damage.

The Red Cross sheltered about two dozen people Friday and Saturday but most displaced residents found their own lodgings with friends or at hotels and motels. Some initially stayed in their cars, McCarthy said.

Sierra Madre, 7 1/2 miles from the epicenter under the San Gabriels, was most severely affected.

“It hit a very small community very hard,” McCarthy said.

The Red Cross also fielded crisis intervention experts to help quake victims. Most needing help suffered from mental fatigue, she said.

Excluding city buildings, Pasadena counted 380 structures damaged at a loss of $12 million as of Monday, Nollar said.

Twenty-five buildings had to be closed for safety reasons, including badly damaged Westminster Presbyterian Church.

Typical damage to Pasadena’s commercial buildings was limited to parapets and other parts of facades, Nollar said.

Toppled chimneys were common in residential areas, along with shifting of homes that weren’t secured to foundations.

The landmark domed City Hall had only superficial damage, while cast stonework at the front of the main library came loose but did not fall. The garage area of one fire station was closed for reinforcement.

Pasadena has been criticized because its building code does not require strengthening of structures for seismic safety until a change of use.

Nollar, noting the city is in the process of changing the code, said buildings that had undergone the work came through the quake without serious failure, although some of those had parapet damage.

“We have several hundred unreinforced masonry buildings that had been upgraded. Although they had not been immune from damage, we did not have any buildings that suffered irreparable (damage),” he said.

About 500 buildings remain in need of seismic upgrading.

A square block of pre-1900 buildings in the city’s revived Old Pasadena area survived the temblor, probably because restoration was under way.

“Fortunately it happened after much of the strengthening of the original facades had already been completed,” Nollar said.

Most repairs could be finished within a few months, but past experience shows that some will languish for a year, usually while victims try to arrange financing, he said.