Story highlights The maintenance team chief "mistakenly performed an action not directed by the technical guidance"

Air Force officials say the 2014 incident did not result in injuries or any threat to public safety

Three airmen who lost certification have been retrained and are back on the job

(CNN) Three U.S. Air Force airmen were stripped of their nuclear certifications after a "mishap" caused approximately $1.8 million in damage to an intercontinental ballistic missile in 2014, officials said Friday.

The incident occurred when the Minuteman III nuclear missile, assigned to the 90th Missile Wing at F.E. Warren Air Force Base in Wyoming, became "non-operational" during a diagnostic test, according to a statement released by the Air Force.

While troubleshooting the issue, the maintenance team chief "mistakenly performed an action not directed by the technical guidance," the statement said.

Air Force officials did not specifically address whether radioactive material was released when the missile was damaged, but said the incident did not result in any injuries or threaten public safety.

Further details about the nature of the "mishap" are murky, as the full report from the military's Accident Investigation Board remains classified.

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