The SCP Foundation: SCP-076
Containment Area-25, which previously housed SCP-076, once detonated its on site warhead as a last attempt to contain SCP-076-2 while it was attempting escape, resulting in total destruction of the site and all on-site personnel. SCP-076-1 survived. The Foundation passed it off as the 1980 eruption of Mount St. Helens.
Oder SCP-294.