- "What are they doing?"
- ―Officer Wirtz on the Diggers [src]
Wirtz noticed the diggers, and, wondering what they were doing alerted other members of Zion command. Lock was informed and as a result declared the breach of Zion's walls was only a matter of time, advising the Council members to join the rest of the non-military personnel inside the Temple.
While the crew of the Osiris had noticed the diggers in the Machine army before, the ship's subsequent destruction meant that only the presence of sentinels was known; Wirtz was the first after them to discover their presence.