I don't know about any books that have the location you mentioned in mind, other than maybe the SOX(which is roughly where Luxembourg used to be).
For a city-wide quarantine though, the way I'd do it is over the course of a couple sessions. Basically one where weird shit starts to happen, you set the tone, people are freaked out, paranormal investigators have their hands full, etc. Then the weird shit turns dangerous, maybe hauntings start involving injuries, people going missing, spirits being openly hostile, even civilian deaths. At this point the city's small police and security agencies are overwhelmed, and unable to cope with the rapidly changing situation with the spirits.
Enter corporation X. A corporation that had investments in the city or surrounding area comes in and agrees to contain and resolve the situation before it can spread beyond the city to other populated areas. Unfortunately for the people in the city, this means military patrols, massive Astral watch and barriers, the corporation's magic users and spirit assets on active watch, etc.
As for the players, if they're just office workers, maybe they get wind of rumours that the regular citizens of the city are being "interrogated" by the Corp and aren't heard from afterwards. Or spirits going nuts killing and torturing people doesn't sound fun. Or maybe on the way home one night they see something they shouldn't involving the Corp and it's plans for the city that freaks the shit out of them and leads them to really, REALLY want to get put of the city ASAP.
Anyways, it's your game, you're the GM, but that's how I'd do it. The "friendly corp is here to help but is actually out to get us" angle would just give regular office workers a good reason to disappear into the shadows, and maybe leave them with few choices except to try their hand as low-level runners (queue Runner origin story intro).