USS Nimitz

From SGCommand

The USS Nimitz (CVN-68) was a supercarrier in the United States Navy, the lead ship of its class. It was one of the largest warships on Earth.

The White House lost contact with it when Earth was attacked by Anubis. The ship was most likely destroyed with all the crew. (SG1: "Lost City, Part 2")

[edit] Behind the scenes

In real life, there is an aircraft carrier called the USS Nimitz, and it is still in service.