San Marcos, CA (CBS) - Fire crews expect another day of challenging conditions as dangerous wildfires near San Diego may be turning deadly.
A badly burned body was found Thursday in a transient camp in Carlsbad - the first apparent fatality. Flames lit up the night sky Thursday as firefighters tried to contain the most stubborn wildfire still burning in San Diego County. The winds turned erratic and unpredictable, making the firefight all the more difficult and dangerous.
"We've had very extreme fire behavior [Thursday] once the winds picked up," Ed Hadfield, a battalion chief for the Santa Maria Fire Department, told CBS News correspondent Carter Evans. "The fire jumped our containment line and really took off. We had a number of fire whirlwinds that were going on, down-canyon winds that were pushing the fire very erratically."
On Friday morning, winds were dying down and temperatures were cooling. A day earlier, the wind was so fierce it created so-called "firenados" - fast-moving swirls of intense flames. Over a two-and-half hour period, what started as a few puffs of smoke soon blackened the sky.
Nearly 16,000 new evacuation orders were issued in San Marcos and nearby Escondido Thursday. Over the last four days, officials have told 125,000 people to leave their homes. More than 2,500 firefighters are working across San Diego County aided by water-dropping aircraft.
The weekend before nine wildfires erupted in the San Diego area, scores of state firefighters were sent along with engines and aircraft to the region - knowing that the forecast of a heat wave and gusty winds was setting the stage for a tinderbox.
The positioning of crews was among several steps fire officials say they have been fine-tuning since 2003 when the San Diego area experienced one of the worst infernos in California's history. Communications between firefighting agencies has improved, residents are notified more quickly when to evacuate, and more aircraft are available to dump water on fast-moving flames.
With cooler temperatures forecast, there was an overwhelming sense that far more damage could have been inflicted on a region of more than 3 million people.
This week's unseasonably early wildfires have driven tens of thousands from their homes and shut down schools and amusement parks, including Legoland, which reopened Thursday. Flames have charred more than 15 square miles and caused more than $20 million in damage, burning at least eight houses, an 18-unit apartment complex and two businesses. A Camp Pendleton Fire Department firefighter was treated for heat exhaustion while battling a square-mile blaze on the Marine base.
San Diego County had some of the strongest Santa Ana winds Wednesday, with gusts reaching up to 50 mph, which may have set conditions for fires to be easily ignited, just as they were in 2003. The 2003 Cedar Fire scorched more than 437 square miles, nearly 3,000 buildings - including more than 2,000 homes - and killed 15 people before being contained.
The tragedy led to California creating one of the world's most robust firefighting efforts, which resulted in the smooth evacuation of thousands this week and crews able to save hundreds of homes from being consumed by the fast-moving wildfires, said Battalion Chief Nick Schuler of the California Department of Forestry and Fire Protection.
Before another devastating wave of fires swept the San Diego region in 2007, the city and county introduced a 'reverse 911' system of automated calls to homes and businesses. Previously, evacuations were accomplished by going door to door or driving down the streets with loudspeakers.
Upgrades at dispatch centers have allowed firefighting agencies to share resources far more quickly by computer, a contrast to 2003 when agencies had to pick up the phone to move engines around, said David Allen, division chief for the state firefighting agency.
There is also a stronger relationship between the state firefighting agency and the military, which had 22 aircraft fighting the fires Thursday.
Those procedures are expected to be tested further as drought-plagued California heads into the summer months of what is expected to be one of its busiest firefighting seasons yet.
Jeff Bowman, the former city of San Diego fire chief who was on duty for the 2003 firestorm, said the outcome of this week's blazes was what everybody hopes for, but several factors worked in firefighters' favor that weren't in place in 2003 and 2007.
In 2003, firefighters from San Diego were deployed all over the state, where multiple fires were burning, and other counties didn't have resources to send because they were battling their own blazes.
"Our guys were fighting in other counties and other counties had nobody to send us. That's a very unique thing that's happening right now," Bowman said. "The other guys are sending guys to San Diego and that didn't happen before."
Also, new construction standards that arose from 2003's devastation helped protect homes.
And finally, the fires Wednesday broke out during the mid-morning and afternoon, when residents weren't as likely to be home and when helicopters from all agencies could fly.
"If San Diego County is so well-prepared for fire, do they have any more firefighters on duty today than they did in the 2003 and 2007 fires? The answer is no," he said. "So why is there a significant different in the outcome? The answer is, the circumstances surrounding where and when the fire started."
It could take months to find the causes of the blazes concentrated in the northern San Diego and its northern suburbs, from the coast to areas 10 to 15 miles inland. San Diego County Sheriff Bill Gore said arson will be among the many possibilities that investigators will look at in trying to determine what caused nine fires to break out during a heat wave, including eight in one day. The first fire started Tuesday.
© 2014 CBS Interactive Inc. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed. The Associated Press contributed to this report.