A Minuteman III, America's only land-based ICBM, is said to have become non-operational during a diagnostic test, which was conducted on May 16, 2014. The chief of the maintenance team and two other airmen, whose identities were not revealed, did not correctly follow the technical guidance while trying to fix the missile and damaged it in the process.
The three airmen, who had their certification removed following the mishap, were retrained and certified to work with nuclear weapons more than a year later.
The Accident Investigation Board, according to the Associated Press, later released a report into the incident. These documents are usually accessible as public records. But Gen. Robin Rand, Commander of Air Force Global Strike Command, sealed the report on November 9, 2015 since the information it contains was deemed "too sensitive to be made public."
"The incident did not result in any injuries, prevent the Air Force from meeting its ICBM requirements, or create a hazard to public safety," Reuters quoted the Air Force as saying.