The Battlestar Columbia is a Colonial Battlestar destroyed at the peace conference.
Cadet Cree claimed to be from the Columbia but Centurion Vulpa said that is impossible since the Columbia was destroyed.
1-Many fans believed tha the Columbia to be the battlestar class name but there no canon or non-canon evidence to support this.
2-Columbia is not named as one of the five Battlestars at the Battle of Cimtar. So is unknown what Vulpa was referring too or where the Columbia was destroyed.