SALT LAKE CITY -- Investigators donned gas masks, air tanks and hazardous materials suits Sunday as they searched a home and three West Jordan, Utah, storage units for any signs of the toxic material ricin.
FBI and a slew of local police and fire officials spent the day searching the home of Thomas Tholen, whose cousin, Roger Von Bergendorff, 57, remains comatose in a Las Vegas hospital after possibly being exposed to the deadly material.
Officials recovered vials of the toxin from Von Bergend-orff's motel room last week, FBI officials said.
Because agents searched under sealed warrants, FBI officials were tight-lipped about materials recovered from Tholen's home and about what led investigators to search the storage units rented to Von Bergendorff.
"It's pretty bad stuff," Tim Fuhrman, FBI special agent in charge for Salt Lake City, said of ricin. "There is clearly a concern from both a public safety and law enforcement experience, when an individual tests positive for ricin."
Authorities and paramedics descended on Tholen's home at 3004 W. 13400 South on Saturday. By Sunday morning, two blocks of the street - from 2900 West to about 3100 West - were choked by police, hazmat crews, fire engines, an explosive ordnance disposal unit, and an FBI mobile command unit. Traffic was blocked from the area.
It was a similar scene at Jordan Self Storage, 9528 S. Bagley Park Road (5230 West), where crews searched storage units rented by Von Bergendorff.
"We are comfortable we are looking in the right places," Fuhrman said.
Due to the deadly nature of ricin, authorities were being methodical in their searches and weren't expected to complete the task until late Sunday evening, said Juan Becerra, an FBI spokesman.
Shortly after 7 a.m. Sunday, Riverton police Lt. Rod Norton and Mayor Bill Applegarth knocked on doors warning several residents that authorities would be looking for dangerous chemicals in Tholen's home and placed them on a voluntary evacuation, said Lt. Paul Jaroscak, a Salt Lake County sheriff's spokesman. That evacuation was lifted by mid-afternoon.
Tholen, his wife and daughter each tested negative for ricin exposure, and Tholen is cooperating with the FBI, Fuhrman said.
On Feb. 14, Von Bergendorff checked into a hospital complaining of respiratory problems, authorities have said. Tholen visited Von Bergendorff's motel room eight days later.
Las Vegas police later recovered firearms, vials of ricin, and an "anarchist-type textbook" tabbed to a section on ricin and castor beans (from which ricin is made) from Von Bergendorff's room, authorities have said.
"At this point in time, we don't have any indications of any connections to any terrorist act or any terrorist activity, but I will say that is something we will continue to look at," Fuhrman said.
Sunday morning's response concerned many neighbors, some of whom described the area as relatively quiet. Salt Lake County Sheriff Jim Winder said the FBI and police response was to ensure the public's safety.
"The citizens here are extremely safe and we anticipate that they will remain so," Winder said, noting that his department is "deeply integrated" in the FBI investigation.
Once ingested, inhaled or exposed to the skin, ricin binds to cells and prevents them from developing the proteins needed to survive, said Sanwat Chaudhuri, director of the Utah Department of Public Health's Bureau of Environmental Chemistry.
An exposed person who inhales ricin will develope flu-like symptoms and fluid will eventually begin to build up in the lungs, Chaudhuri said.
As little as 500 micrograms of ricin, about the size of the head of a pin, is enough to kill a person. Depending on the amount of exposure, a person can die in three to five days, said Jana Coombs, biological emergency preparedness and response coordinator for Utah Department of Public Health.
The only legal use for ricin is cancer research, according to the Centers for Disease Control and Prevention.email@example.com