The U.S. military said on Thursday it has investigated a rumor spread by city officials in Pyeongtaek, South Korea, about a dangerous leak of white phosphorus at the Osan Air Base, and determined there was never any such leak.
The Pyeongtaek city government sent a burst of text messages to residents on July 28 warning that white phosphorus – a dangerous incendiary substance – had been leaked at the air base.
The text messages advised residents to relocate to safe shelters and avoid exposing their skin to any suspicious substances. City police formed a safety perimeter around the base and rerouted traffic.
The U.S. 51st Fighter Wing released its own statement on July 28, establishing a safety cordon a bit smaller than the one put up by Pyeongtaek police, “due to a ground mishap and out of an abundance of caution.” The U.S. statement did not provide details of the “mishap,” and did not advise an evacuation of the base or surrounding area.
“We are handling this matter with the utmost care and expediency. The safety and well-being of our service members, their families, and our Pyeongtaek neighbors remain our absolute highest priority,” the 51st Fighter Wing said.
The evacuation order from the city of Pyeongtaek was rescinded within a few hours, with no injuries, damage, or major disruptions to city life reported. The city claimed it had consulted with the U.S. military and South Korean emergency response officials before sending out the alarming text messages.
On Thursday, U.S. Forces Korea (USFK) concluded its investigation of the incident, finding that some residue had been discovered during a routine maintenance inspection on July 28, but it was not white phosphorus, nor was it hazardous in any way.
“After follow-on analysis, we are confident that the residue was non-hazardous surface corrosion resulting from environmental exposure over time,” a statement published on the Osan Air Base website said.
“Our emergency response professionals responded immediately using layered protection protocols to ensure full containment of the munitions. No injuries occurred, and base operations are proceeding normally,” the statement said.
“We deeply value the trust of our Pyeongtaek neighbors and are committed to keeping everyone safe, informed, and updated,” it added.
Col. Ryan Ley, commander of the 51st Fighter Wing, stressed the importance of safety at the base, and thanked the city government for its cooperation.
“Safety is paramount, and we care deeply about the well-being of our service members, their families, and our Pyeongtaek neighbors. We appreciate the city’s close partnership in keeping our community safe, and we thank everyone for their patience as our team worked to resolve this situation,” he said.
None of the U.S. statements on Thursday speculated where the rumor of a white phosphorus leak might have originated, or criticized Pyeongtaek officials for over-reacting to the incident.
Master Sgt. Eric Flores, a spokesman for the 51st Fighter Wing, told Stars and Stripes the incident involved an “isolated munitions storage area inside the base,” and the “incorrect evacuation message” originated with At Hoc, a mass-messaging system employed by the base.
“We routinely check our munitions and regularly conduct inspections to ensure our inventory is fully accounted for and secure,” Flores explained, saying that when “munitions that require specialized handling” are involved, instructions for establishing a safety cordon are broadcast automatically.
The false white phosphorus alert – reported as a matter of fact by some Korean media – spread widely enough to get the South Korean national government involved. Korea Joongang Daily (KJD) reported on July 30 that the government was “in talks with the U.S. military to gain access” to Osan Air Base for an inspection after the reported chemical leak.
“We plan to conduct air quality monitoring near the site where the leak occurred to ensure no safety hazards are present for residents,” a South Korean official said.
The white phosphorus rumor also sparked a protest by a group of radical left-wing activists at Osan Air Base on August 4. The police arrested eight “liberal student activists” who “rushed the compound” during the demonstration.
The activists brandished anti-American slogans, such as “Let Us Destroy the U.S. 7th Air Force,” and lumped other issues in with the white phosphorus rumor, including alleged American opposition to a semiconductor plant that would be built near U.S. military facilities. The organizers, known as the Korean Progressive Student Union, said they were opposed to “the war schemes of the two imperialist powers, the U.S. and Japan.”
On Thursday, police said they have requested arrest warrants for four of the student activists involved in the Osan Air Base protest. The four were taken into custody by U.S. Forces Korea after getting past the main gate of the air base, and were subsequently handed over to Pyeongtaek authorities.