Aftershock Raises Questions About New Deductibles : Insurance: Companies are weighing whether Sunday’s damage will be considered separate from Jan. 17 quake.

Some Southern California residents who suffered property damage in both the Jan. 17 Northridge earthquake and Sunday’s powerful aftershock may have to meet their earthquake insurance deductibles all over again, insurance company officials warned Monday.

Most insurers said they will individually review claims from Sunday’s 5.3-magnitude aftershock before deciding whether to classify any new damage as part of the January quake or as an entirely separate incident.

For many homeowners, much rides on the outcome because earthquake insurance deductibles typically run 10% of the coverage limits, easily tens of thousands of dollars in most cases.

Sunday’s aftershock centered near Panorama City triggered a new moratorium on the sale of earthquake insurance by several large insurers, making coverage more difficult to buy in Southern California for at least the next several weeks.

Farmers Insurance Group, Safeco Insurance Cos. and 20th Century Insurance Co. all suspended writing earthquake policies in the Los Angeles area for up to 30 days. However, State Farm Insurance Cos. and Allstate Insurance Co., the two largest carriers, are continuing to sell new policies.

Although damage from the latest quake appeared relatively slight Monday, it raised concerns among homeowners about how their insurers will treat new claims.

John Mora, whose home in the Winnetka neighborhood of Canoga Park sustained $10,000 to $11,000 damage in the Jan. 17 quake, said a bookshelf toppled over and was smashed in the Sunday afternoon aftershock and that a new crack sprouted in the foundation of his garage.

Mora called his State Farm Insurance agent Monday and was unprepared for what he heard. “He told me it looks like it’ll be considered a new quake and I’ve got to pay my $5,000 deductible again,” Mora said.

State Farm Vice President Roger B. Tompkins said the company has no blanket policy for handling claims from Sunday’s aftershock. If damage appears to be related to the Jan. 17 quake, it will be added to the original claim, he said. But if the damage is unrelated, it probably will be considered a separate incident, requiring the claimant to meet the entire deductible anew.

“It is technically considered a separate insurable event,” Farmers spokesman Jeffrey Beyer said of the aftershock. However, he also said Farmers will consider claims case by case.

Meanwhile, insurers continue to boost their estimates of damage from the Northridge quake, increasing the likelihood that total insurance losses will far exceed the official industry estimate of $2.5 billion.

Allstate nearly doubled its damage estimate Monday, saying it now expects to pay about $600 million on some 38,000 claims. Its initial estimate in early February was $350 million on 25,000 claims.

When Allstate issued its new damage estimate from the Northridge quake Monday, it was the second large carrier to project a sharply higher total.

Last Thursday, Woodland Hills-based 20th Century pushed its claims cost estimate up to $325 million from $160 million and said the losses would result in a $161.7-million charge against first-quarter earnings.

Stock in the insurer’s parent firm, 20th Century Industries, dropped again Monday, closing at $20.25 a share on the New York Stock Exchange, down $1.25 for the day and down 24% from Thursday’s closing price of $25.125.