AFTER THE RIOTS : Tally of Riot Fires in L.A. Drops to 623 : Survey: City Fire Department’s count falls sharply from earlier estimates. Officials again appeal to arson witnesses to come forward.

The number of structures set afire during the riots was 623 in the city of Los Angeles--far fewer than the thousands suggested by early response data, according to a new survey conducted by the Los Angeles Fire Department.

Officials also urged witnesses to the arsons to come forward, saying that, lacking more evidence, the number of cases officials will be able to prosecute will probably be low. Many of the structures burned to the ground, incinerating evidence normally available to prosecutors.

“My hunch is that there is a treasure-trove of information out in the community that hasn’t reached investigators yet,” said head Deputy Dist. Atty. Frank E. Sundstedt, who is in charge of a multi-agency task force charged with prosecuting arsons and other crimes committed during the riot. “Unless and until it does, many of these burns will go unsolved.”

The Los Angeles Fire Department previously reported that it responded to 5,537 structure fires between April 29 and May 5, but has since determined that many of those responses were actually to multiple 911 calls about the same blazes.

“Based on our survey, 623 structure fires is the best we can come up with,” said Los Angeles Fire Chief Dean Cathey. “In many cases, the initial calls to 911 were the wrong address, false alarms, places we had already been to, or as many as 10 people calling to what appeared to be a different fire nearby. That’s why there was such a discrepancy.”

Notices have been posted at all burn sites asking anyone with information about the fires to call the Fire Department, but few calls have been received, he said.

“The number of tips we’re getting is only about five a day, and most are not too fruitful,” he said, asking that anyone with specific information about arson during the riot to call either 213-485-2225 or 213-485-7300. The Los Angeles County Fire Department’s tip line is 800-244-2322.

As of late Thursday, city arson teams had investigated 496 of the structure sites, yielding just 49 arrests, he said. Many of the arrests were made either during the riots or shortly thereafter as a result of eyewitness reports. Of those, eight may involve owner insurance fraud, he said.

Not all those arrested have been charged.

Sundstedt said Thursday that 21 have been charged with arson-related crimes by his office, seven of them juveniles and one a businessman who allegedly set fire to his own store. Other investigations are underway.

“Normally when firefighters respond to a fire, they follow right up with an investigation,” Sundstedt said. “Here we don’t have that luxury.”

To help bolster otherwise difficult-to-prove arson cases, Sundstedt said, officials are hoping to use tapes of calls made to 911 at the time the fires broke out.

“If we can’t establish by physical evidence at the scene that the crime of arson was committed independently of any admissions of a perpetrator, one of the ways to establish the crime might be someone calling 911 saying, ‘Someone just threw a Molotov cocktail through the store window,’ ” Sundstedt said.

Downward adjustments in the number of arson fires also were being made by fire departments in other areas affected by the riots.

Bob Caldon, public information officer for the Long Beach Fire Department, said thousands of calls were received between April 29 and May 4. “A lot of those were repeats, rekindles and restarts,” he said.

Initial reports suggested 340 structures were set on fire in Long Beach during the riot period, he said. That estimate has now been reduced to about 170.

“We’ve been real fortunate with citizen tips, I don’t know why,” he said, adding that citizens are still stepping forth daily with tips and occasional home videos.

He said Long Beach officials had made six arson-related arrests so far, five involving two businesses in which owners purportedly helped torch their own buildings. The sixth suspect was a looter-arsonist, he said.

The number of fires reported by the County Fire Department and the cities most heavily damaged in the riots--Los Angeles, Long Beach, Compton, and Inglewood--is believed to be about 1,100.

According to city Fire Department definitions, a fire that destroys a mini-mall of stores under a single roof counts as one fire. Damage estimates are still not available from most agencies.