Contractors preparing to demolish a vacant west side Eau Claire building in late April found a small metal box in an old walk-in safe and got a bad feeling about it.
Painted red, the box contained a U-shaped vial of liquid and it was accompanied by a sign that said “Detour Safe Protector.”
What they’d stumbled onto was a booby-trap device used to protect a safe’s contents by dispersing a cloud of tear gas at would-be burglars, sending them fleeing to relieve the resulting severe cough, eye and skin irritation.
Upon finding the red box, the contractors left the device in the safe on April 23 and contacted the city so the Eau Claire Fire Department’s HazMat team could respond and investigate.
Equipment that detects chemical and radioactive threats in the atmosphere led the way into the building so the team could determine it was safe to get a better look.
“That allowed us to get close enough to carefully handle the device and take pictures,” said Matt Jaggar, battalion chief.
Still unaware of exactly what chemical was inside of the glass vial, the team then withdrew to do research and consult professionals.
They determined it contained one of two chemicals used during World War I — likely chloropicrin or maybe phosgene — as toxic gas and then later included in commercial anti-burglary devices sold in the first half of the 20th century.
“If you research those, they were pretty unique and pretty substantial,” Jaggar said.
The chemicals pose an immediate health threat to those exposed to them, he noted, and can also be a minor explosive hazard.
Starting in the 1920s, these theft-deterrent devices began coming with safes and vaults or were after-market additions to them, according to an incident report from the U.S. Centers for Disease Control that described what happened when one of them was accidentally triggered in Wisconsin.
On Dec. 4, 2003, the owner of a Beloit jewelry store became curious about the device attached to an old safe and began tightening a screw on it, according to the CDC. The screw cracked the liquid vial and released about four ounces of tear gas. The shopkeeper suffered eye and skin irritation but was treated at a hospital and released.
The jewelry store and adjacent businesses were evacuated while a HazMat team and other emergency workers dealt with the situation.
One of the major manufacturers of the devices was located in Wisconsin and made them from the 1920s through 1950s, according to the CDC. The one discovered in Eau Claire in April was sold by the Didier Safety Equipment Co. of Minneapolis, based on the ID tag that accompanied it.
After learning more about the device they discovered, Eau Claire’s HazMat team contacted local company WRR Environmental Services, which removed the device and safely disposed of its contents.
The CDC advises that people who encounter older safes — namely bankers, jewelers and locksmiths — know how to identify these devices. If they find one, they should contact a HazMat team or a locksmith trained on how to dismantle them.
An October 2013 post on a blog called “Safecracker at Large” written by San Francisco area licensed safe and vault technician Ken Dunckel, explains how the devices worked.
They were rather simple glass tubes mounted inside a metal housing that was attached to safe doors near the lock. Burglary methods were pretty crude back then, involving brute force focused on destroying the locking mechanism, the Dunckel explains. The anti-theft devices counted on that attack breaking the glass vials of liquid, which turned into tear gas when exposed to air, sending the burglars fleeing to relieve the ensuing cough and burning in their eyes, noses and throats.
This kind of booby-trapping is illegal today, but with the durability of safes, they tend to stay in operation for a long time. Dunckel noted that it’s becoming increasingly uncommon to find the devices though as they’ve been removed and disposed of as locksmiths and others come across them.