The Avalanche
In 2016, 9 Roaming Portals were attacked on the same day. There are so many Portals around the world that nine attacks is not particularly odd. However, because of the transience of Roaming Portals, even one Roaming Portal being attacked for any reason is atypical. The details of the attacks are not popular conversation for a variety of reasons. Firstly, Beings simply have other interests and there are many who don't even know it happened, much less know of its unique distinction. Many Beings are not even aware of the existence of Roaming Portals outside of legends and whispers. One of the Roaming Portals (Special Portal 3461) that was attacked had been consistently emerging near A large Portal, ID 17555. Many of the Beings had become accustomed to the additional resources and networking opportunities that came along with two thriving communities in close proximity. The Special Portal 3461, never in one place for too long, allowed for interactions in a way that reduced conflict.
After the attack Special Portal 3461 went dark, at least for Portal 17555. Portal 17555 then dispatched investigators to determine what had happened. After 2 years, all of the investigators died under mysterious circumstances. The last 2 investigator's bodies were discovered in an avalanche despite having checked in 10 minutes before the avalanche was recorded, and they were nowhere near snow. The only information the investigation had produced was that 9 Roaming Portals were attacked, seemingly in concert.