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Volume 90 Issue 17 | pp. 38-39
Issue Date: April 23, 2012

Burning Down The House

ACS Meeting News: How investigators discovered and destroyed an explosives-filled home
Department: Science & Technology
News Channels: Environmental SCENE
Keywords: San Diego, Escondido, bomb house, explosives house, explosive, Jakubec, HMTD, PETN
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Jakubec freely mixed personal and chemical items.
Credit: San Diego County Sheriff’s Dept.

On Thursday, Nov. 18, 2010, a gardener was seriously injured when he stepped on some gravel in the yard of a San Diego-area home and the ground exploded beneath his feet. Subsequent investigation of the house and its grounds revealed what authorities called the largest cache of homemade explosives ever found in the U.S. They deemed the house too dangerous to clean out and burned it down instead.

At the American Chemical Society national meeting in San Diego last month, in a symposium organized by the Division of Chemical Health & Safety, officials described how the incident unfolded.

Fire and ambulance crews initially responded to the scene; then they called the San Diego County Sheriff’s Department when they realized that the gardener’s injuries were from an explosion, said Nick Vent, an environmental health specialist in the Hazardous Materials Division of the San Diego County Department of Environmental Health.

Sheriff’s officers subsequently took the house resident, George Djura Jakubec, then 54, into custody for questioning; brought in bomb squad and hazmat crews; and evacuated the neighbors. The property is in a residential area, on unincorporated land but surrounded by the city of Escondido in northern San Diego County. It is also a few hundred feet from Interstate 15.

Technicians searching the grounds initially turned up six quart-sized jars filled with a white substance, 200 lb of lead sheeting, and gallons of concentrated acids as well as chloroform, hexamine, acetone, and hydrogen peroxide. Officials searching records on the property and on Jakubec learned that he had purchased castor plants. The poisonous protein ricin is isolated from castor bean oil.

The discoveries left investigators concerned about explosive, radiological, chemical, and biological hazards at the site. To determine what was there, Vent and colleagues took air samples for biological agents and combustible compounds and sent in radiation detectors with the bomb technicians who searched the property while outfitted in both explosion and hazmat gear. Also key to the investigation was a portable Raman spectroscopy unit with a flexible sampling probe that could analyze the contents of the jars through the glass, without moving the jars or unscrewing their metal lids, because technicians feared that the contents were friction- or shock-sensitive.

Adding to the danger of the situation were a few previous reports across the U.S. of portable Raman lasers causing samples to explode. “If you point the laser at a dark-colored substance, it will ignite,” said John Johnson, director of safety and security at Thermo Fisher Scientific, which manufactures the instrument used in the Escondido response. “When you’re pointing the laser at 1.5 lb of explosives, you have to take that into consideration.”

A two-minute-delay timer on the Raman unit was therefore also a critical feature, so a bomb technician could set up the unit and retreat to a safe distance before the laser fired. It took a few tries to figure out how to get good spectra through the thick glass of the jars, Vent noted, but investigators eventually identified the jar contents as hexamethylene triperoxide diamine (HMTD), an explosive compound that is sensitive to heat, shock, and friction.

On Friday, Nov. 19, officials shut down I-15 while a robot picked up the jars one at a time, moved them to a relatively safe location, and detonated them.

Meanwhile, officials were still concerned about explosive residue on the ground. A bomb technician, in full protective gear, survived an explosion in the yard that was similar to the one the gardener overcame. After the jars were gone, technicians sprayed the grounds with a 5% sodium hydroxide solution to try to neutralize whatever was left.

On Sunday, Nov. 21, investigators at last entered the house. “We assumed that most of the bad stuff was in the backyard and the house was going to be a piece of cake,” Vent recalled, chuckling at how wrong they were.

Although technicians found no radioactive isotopes and no biological agents—just castor beans—they discovered thousands of rounds of ammunition; a hand grenade mold and homemade grenades; human face molds and masks; Escondido Police Department shirts; more concentrated acids and hydrogen peroxide; jars of thermite, erythritol tetranitrate, pentaerythritol tetranitrate (PETN), and more HMTD; and a layer of white powder all over the hardwood floor that was too thin to identify. Jakubec had bought the acids and hydrogen peroxide at low concentrations and distilled them to yield concentrated solutions.

The chemicals, ammunition, and grenades coexisted with other household items in a crowded mess. “Cleanliness was not next to godliness” for Jakubec, Vent said. The conditions made it tough for people to maneuver safely in the house, and using robots was out of the question.

“At this point the techs were coming out of the house saying, ‘This is nuts!’ ” Vent said. The house showed evidence of previous explosions—walls were damaged and Jakubec’s distillation apparatus was in ruins—but neighbors had attributed the noise to vehicles backfiring on I-15, Vent said.

As investigators realized the magnitude of what they had on their hands, the question they faced was whether they could ever clean up the property to the point that a family could reside there again, Vent said. To help them figure out what to do, officials reached out to other agencies that deal with explosives, including the Federal Bureau of Investigation and the Bureau of Alcohol, Tobacco, Firearms & Explosives, as well as explosive ordnance disposal specialists at nearby Marine Corps Base Camp Pendleton and Air Station Miramar.

At a meeting on Monday morning, Nov. 22, the consensus was that authorities had to burn down the house. Although they could continue to pick it apart piece by piece, it would be at least a year of painstaking, dangerous work with a high probability of someone accidentally setting off an explosion or fire, Vent said. Planning and controlling a burn was the best solution to ensure the safety of emergency personnel and the surrounding community.

But it was not an easy decision to make. “I’m a firefighter, and we usually put fires out” rather than start them, said Todd Newman, chief of the San Marcos Fire Department, which had jurisdiction over the property. He added that there were concerns over the legality of destroying the house, especially because Jakubec was not the owner, as well as about liability for surrounding homes. And residents living downwind might be exposed to fire emissions. “How are we going to have certainty that no one will be harmed?” Newman recalled asking.

Careful planning provided this assurance. Vent and colleagues talked to anyone and everyone they could think of, from federal agencies to academic scientists, to get some insight into how to do the burn so there would be no surprises and to minimize effects away from the property, he said. The approach they settled on involved keeping most of the house shut to ensure that the temperature got high enough to destroy whatever was inside and to contain any explosions—the goal was to have everything burn inside, then have the walls come down. Holes in the roof would provide ventilation.

As for the immediately neighboring houses, which were terraced so that one was slightly above Jakubec’s and one was below, officials at first thought that the house above likely would not survive the burn. But then they came up with the idea of building a fire wall to protect it, Newman said. The fire wall was similar to what might be found separating a garage from a house in a typical residence but with double the drywall and a layer of fire-retardant gel commonly used to coat homes in wildland fires.

Vent and colleagues had already been running atmospheric-modeling studies several times a day in case the house went up in flames on its own. In planning the burn, they used similar modeling to find the right weather conditions to send smoke and emissions straight up into the atmosphere to dissipate there rather than blowing over the community and to define evacuation and shelter-in-place areas.

Overall, the modeling was easier said than done, because common modeling programs didn’t have the necessary capabilities, Vent said. Software developed by the Environmental Protection Agency and the National Oceanic & Atmospheric Administration, for example, can only do a static release of one chemical at a time. Officials needed something that could handle multiple compounds at once and account for reactions between the compounds and their degradation products. Eventually, they got access to a classified program from the Defense Threat Reduction Agency.

Plan in hand, authorities presented it to a skeptical community at a town hall meeting on Tuesday, Nov. 30. They also put information on the county website, and sheriff’s officers went door-to-door and made calls to homeowners. “There was no doubt in my mind that we were going to do this and do it successfully,” Newman said. But “our job at this point was to calm the nerves of so many people who thought this was going to be the end of the world as they knew it in their neighborhood.” Most people, however, seemed to leave the meeting convinced that officials knew what they were doing, he said.

Also on Nov. 30, the county and state declared states of emergency, which gave officials the legal authority they needed to burn the house.

On Thursday, Dec. 9, the day of the burn, everything went perfectly: A command post kept 300 people from 60 agencies informed as the weather cooperated. Officials evacuated residents, applied the gel to the fire wall, shut down the freeway again, placed igniters to start the fire, and set the house alight. The house burned exactly as anticipated. As the smoke rose 2,600 feet in a vertical plume, air monitors showed that emissions never exceeded exposure limits. The fire wall held, and the only item that appeared to escape the confines of the house was a single bullet found 10 feet away. Temperature-sensitive strips placed in the yard showed that temperatures there exceeded 250 ºF, ensuring that any remaining HMTD or other residue had decomposed.

“It was a textbook lesson in the value of all of the money that the U.S. government has spent following Sept. 11 in preparing our first responders to handle something really bad,” said Neal Langerman, founder of Advanced Chemical Safety and organizer of the symposium.

After the burn, contractors removed ash, debris, and soil from the property and tested what was left over to ensure that no chemical or heavy-metal residue remained. On Dec. 28, authorities released the property back to the owner.

From start to finish, the response cost $1.5 million, Vent said. The county denied a claim by the property owners for $500,000 for losses and emotional distress.

As for Jakubec, he pleaded guilty to repeated armed bank robbery and is now serving a 30-year prison sentence. He declined to say in court why he made the explosives, and investigators could find no links to terrorist or drug organizations.

“My personal opinion, based upon what I saw, is he just wanted to know whether he could actually do some of these things,” said sheriff’s lieutenant Mike McClain. “I don’t think we’ll ever completely know exactly what his true motivations were.”


Photo Gallery: Click to here to see photos of the house before it was burned to the ground.


 
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