A surprise seven-hour slugfest in the Fountain war was cut short when a CCP typo brought the system down.
The fight started when TEST dropped an ihub in an attempt to save the Z9PP-H system. The CFC started attacking it, and TEST defended. Ships were traded, and PL and TEST both brought in slowcat carriers to attempt to rep the ihub up. At this point, the CFC formed megas to hit the carriers. When the megas came in, the PL carriers got out safely, but the TEST carriers were pinned down, slowly but steadily dying.
The battle was completely unplanned; as such, Z9PP was sitting on an unreinforced node. Tidi hit 10% and stayed there, drawing the engagement out. As with Asakai, this allowed both sides time to call in reinforcements. It also built excitement over time, with plenty of uninvolved people tuning in to Twitch.tv streams of the fighting.
With the fight going strong and continuing to escalate, CCP decided to do what they could for the poor node to improve performance as much as possible. This meant removing all non-essential stuff (i.e, all other systems) from the node and mapping them on to new nodes. After that was done, the node's full capacity could be used to handle the ongoing battle.
Unfortunately, it never got that far. According to CCP Phantom, the person who initiated the remap typoed, leaving every system on the node, including Z9PP, remapped somewhere else, ending the fighting ahead of its time. When a node is remapped, it works more like downtime than a disconnect. All ships are removed from space completely, so the 15 minute aggression timer doesn't matter. While the system came back up quickly, TEST's carriers were safe. TEST, seizing the opportunity, told everyone not to log on.
In his post explaining what had happened, CCP Falcon indicated that CCP would be reviewing the events leading up to the failed remap and adjusting procedures to prevent it happening again. While this is the largest fight interrupted by a node remap, it's happened before-- a remap in the J5A fight influenced the outcome, and a surprise reboot saved some CFC dreads. Previously, the DDOS and later unrelated network issues have affected fleets as well. Even ending before its time, it was a bloody battle, but one that could have been bloodier.