The San Diego County Sheriff's Department said the burning of an Escondido home destroyed massive amounts of explosives inside and went off without a hitch.
There were some popping sounds as the chemicals were vaporized by intense heat.
Remotely controlled explosive devices ignited the house. It was quickly in flames.
Most of the home was destroyed in about 30 minutes.
The fire reached about 1,800 degrees Fahrenheit, officials estimated, hot enough to neutralize the unstable explosives inside.
“No readings of dangerous pollutants were detected,” said Robert Kard, director of the county’s Air Pollution Control District. “Because Interstate-15 was closed down in the area, the APCD recorded levels of pollutants lower than we normally have when traffic is on the road. We did not detect any effects of the fire at all.”
Kard said pollution monitors will remain through the end of Thursday.
San Diego County Department of Environmental Health officials told Kard they registered a momentary peak of cyanides from plastics burning in the house.
“It was literally momentary and it went away.” Kard said.
Inside the home was a large quantity of bomb-making materials.
Officers said they found the same types of chemicals used by suicide bombers and insurgents in Iraq and Afghanistan.
The materials included Pentaerythritol tetranitrate, or PETN, which was used in the 2001 shoe-bombing attempt aboard an airliner, as well as in airplane cargo bombs discovered last month by authorities.
George Djura Jakubec, 54, who lived in the house with his wife for about four years, pleaded not guilty Monday to eight federal criminal counts and was ordered held without bail.
The Serbian native, who rented the home, is accused of making and possessing destructive devices, as well as robbing three banks and trying to rob a fourth over the past two years.
After the house in the 1900 block of Via Scott was ignited shortly before 11 a.m., thick black/gray smoke rose vertically. The plume dissipated as light winds carried it east, as planned.
Jan Caldwell, with the San Diego County Sheriff's Department, said popping noises heard during the fire were likely hand grenades and ammunition.
The charred rubble and ashes of Jakubec's former residence will likely smolder through the day, according to Caldwell. Cleanup efforts at the site will begin Friday, she said.
"It's highly unlikely that there's any toxicity (remaining at the site)," the spokeswoman said.
Hazmat crews are expected to sift through the debris after the ashes have cooled.
County officials said the home was packed with so many homemade and highly-volatile explosives, burning it to the ground was the safest option.
Scores of nearby residents were evacuated earlier. Authorities used helicopters and air pollution sensors to monitor the controlled burn for potential health problems.
Crews built a 16-foot firewall and covered it with fire resistant gel to protect the closest homes. Branches of at least one tree caught fire and were quickly extinguished by firefighters.
Earlier Thursday, police opened windows and doors at the home, and drilled holes in the roof. Authorities were given protective breathing masks in case they need to enter the house if the blaze got out of control.
Officials also closed a section of Interstate 15 near the fire, routing traffic on surface streets. A feared massive traffic jam never materialized.
Residents, onlookers and news crews were kept at least 400 yards from the home.
Investigators say they are still trying to understand what motivated Jakubec, to stockpile the material.
In the backyard, bomb technicians found six mason jars with highly unstable Hexamethylene triperoxide diamine, or HMDT, which can explode if stepped on. A coffee table was found cluttered with documents and strewn with detonators, prosecutors said.
The chemicals were found after a gardener accidentally set off an explosion at the home by stepping on what authorities believe was a byproduct of HMTD.
