Van Statten Incident
The Battle of GeoComTex started when the "last" Dalek escaped The Vault in 2012, at the GeoComTex base.
200 security personnel fought the Dalek, but all were exterminated without the chance to scratch it. The Dalek kept travelling through the base, up a staircase and it even turned on the sprinklers (to make the humans' guns short circuit). The Dalek eventually wound up finding Henry van Statten, and nearly killed him.
The Dalek had absorbed Rose Tyler's DNA to regenerate itself and escape. Since it did this, it has been contaminated with emotions. The Doctor was about to blow it up with some alien weaponry, but was convinced otherwise.
The Dalek ended its pain, by self-destructing. The aftermath of the battle was that the base was sealed off, and Henry van Statten's memory erased. (DW: Dalek)
