Star Trek: 12 Biggest Losses Starfleet Ever Faced

Seven.

Million.

People.

The Xindi assault on Earth, caused by false information fed to them by beings from the future, becomes the single most devastating attack on Earth by an alien species in the history of Starfleet. It is a complete tragedy from start to finish - The Xindi were acting for their own self-preservation, only to later discover they were misled.

Enterprise is recalled to Earth in the wake of this attack, travelling at maximum warp while they desperately attempt to find out if they have lost anyone in the attack. For Trip Tucker, the worst is confirmed. The weapon cut a path from Florida to Venezuela. His sister Elisabeth lived in Florida, and was one of the many who died in the attack.

It would take a long time for Starfleet and the Xindi to find common ground - there is a lot of blood that is spilled before this can happen.