Their old service and waste systems.
4 seconds sound clip from the The Matrix movie soundboard.
You can hear this line at 01:00:29 in the Blu-ray version of the movie.
Quote context
[...]
- EMP?
- Electromagnetic pulse. Disables any electrical system in the blast radius.
- It's the only weapon we have against the machines.
- Their old service and waste systems.
- Sewers.
- They used to be cities that spanned hundreds of miles.
- Now these sewers are all that's left of them.
- Quiet.
[...]