The attempted theft of ammonia appears to be the cause of a leak Tuesday morning at the Washington Cold Storage facility in Kent along Railroad Avenue, just south of West James Street.

The leak, which was shut off at about 9 a.m., was from an exterior valve at a local cold storage facility that someone apparently opened without the permission of the business, according to a Kent Fire Department media release. The company uses ammonia in its refrigeration process.

No injuries were reported, said Kyle Ohashi, Kent Fire Department spokesman.

Kent Police are investigating the possible theft of ammonia from the cold storage facility.

Investigators determined the outside pipe, which had been capped, showed evidence of tampering, according to a Kent Police media release. Personnel from the Cold Storage and Kent firefighters were able to re-secure the pipe and stop the leak.

While normally an uncommon theft, people have occasionally resorted to stealing ammonia to manufacture illicit narcotics, according to police. It is unknown if that was the motivation in this case.

“This is an extremely unusual occurrence,” said Kent Police Lt. Pat Lowery. “Any attempt to steal such a dangerous material is foolish and in this case, could have created a significant danger to the public.”

Police are working with neighboring businesses in an effort to locate witnesses and video of the incident.

Firefighters quickly cordoned off a 10-square block area surrounding the business at 621 N. Railroad Ave. Kent Police closed West James Street in both directions between Central Avenue and Fourth Avenue North in order to ensure that no one was exposed to the toxic gas.

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The gas leak also caused officials at Mill Creek Middle School and the Regional Justice Center to put each facility into lockdown, although no gas entered either facility.

As a precaution, Kent School District officials chose to keep the student body inside at nearby Mill Creek Middle School, though the campus was outside the containment area, according to Kent Police.

A passerby called 911 to report the leak at about 6:45 a.m. Tuesday after smelling a gas odor.

Because of the type of gas leak, fire department hazardous material response teams from throughout south King County were dispatched. Teams from Renton, Tukwila, the Port of Seattle and Boeing assisted the Kent Fire Department Hazardous Materials Response Team. King County paramedics and the SeaTac Fire Department’s Rehab unit also responded.

Hazardous materials technicians in fully encapsulating suits were able to shut off the gas leak by 9 a.m. Tuesday. Once the gas dissipated (ammonia is lighter than air), they were able to determine that there were no further leaks.

Tests done by investigators inside of the cold storage facility showed that no gas had penetrated into the structure and employees were allowed inside. It is unknown how much gas escaped out of the exterior valve.

The potential for injuries was very high due to the nature of this caustic compound. Ammonia can be toxic and in a gaseous form will cause respiratory distress and eye irritation.

“Our concern was the airborne gas that can be a respiratory and eye irritant,” Ohashi said.

No employees were in the facility at the time of the leak, but arrived later in the morning and provided critical information about the refrigeration system and valves. The state Department of Ecology and the U.S. Environmental Protection Agency were notified of the leak.

Sounder commuter service and King County Metro services were not closed by the leak because the wind was blowing from the east, but fire officials closely monitored the train and bus area.

Washington Cold Storage has an 18,000-square foot freezer storage facility in Kent to help companies with distribution of products throughout the Pacific Northwest. The company also has a freezer storage facility in Puyallup.