The Catacomb 87 Incident (Eurasian: Incidentia Octagintae-septae Sepulchrae; Lyrian: Zwischenfall der 87. Katakombe) was a disaster which occurred in the Eurasian province of Tolbiacum in the 1966, as part of Operation Mariposa. Catacomb 87 was a bunker operating as part of Operation Mariposa that underwent trials involving the Forced Evolutionary Virus. In 1966, a failure in containment resulted in a series of events with caused an unspecified number of test subjects to free themselves and attack the guards, causing the widespread dispersal of FEV viral material within the bunker itself. The facility was eventually sealed and destroyed as part of a hastily arranged Duresio-Eurasian nuclear test. Its current survival is unknown, as the bunker was designed to withstand a limited nuclear blast, and the area which it formerly inhabited is still guarded by military elements.
The incident is believed to have begun when a test subject infected with a modified strain of FEV broke free from its restraints and attacked research staff, who fled and sealed that portion of the laboratory, but not before security personnel attempted to kill the subject with gunfire, which proved ineffective but damaged the control mechanisms for the doors in that sector. This caused the fire control system to activate, releasing all the FEV subjects in that sector, many already infected and in the process of "transformation" (it is worthy of note that in the leaked Eurasian documents the word "transformation" appears repeatedly).
The sealing of the escaped subjects into one of the sections did not last, however, as they soon broke their way through and again were fired upon by security personnel. The subjects at some point or another managed to damage several of the FEV dispersal tanks in the testing rooms, causing large portions of the laboratory to become infected, as well as many laboratory and security personnel, who eventually made the decision to radio for reinforcements and evacuate the facility entirely. However, the subjects had advanced far into the facility by then, and had cut of whole portions. The military then made the decision to abandon the facility entirely and seal any remaining personnel inside to prevent the subjects from reaching the surface.
The facility was then reported destroyed in what was called a nuclear test, however records show that it was in fact a nearby nuclear submarine which, responding to an urgent Code Feldgeister (the only recorded use of the code in history; code Thanatos signifies that friendly forces have been completely overwhelmed by hostile forces and require immediate deployment of nuclear weapons to deny sensitive material to the enemy), fired a single megaton-range nuclear weapon on the bunker, destroying it and much of the surrounding landscape and preventing the escape of the subjects. This marked the end of the FEV program, as it was realized it was viable in neither an economic or defensive sense, as many of the Ministry of War's brightest minds perished in the blast.
Concerns have been raised in the modern day, especially with the illegal leaking of classified material pertaining to Operation Mariposa, as to whether portions of the bunker survived beneath the blast. Much of the bunker was designed to withstand a nearby, not direct, nuclear blast, and it is entirely possible that portions of the laboratory, buried deep underground, survived. However, the Eurasian Legions control the entirety of the site, and no civilian entry has ever been permitted, with those caught attempting to enter being tried as having committed High Treason and being executed by military courts-martial.