Ensign Diane Atlagic was a female human of Croatian descent who served as an Earth Starfleet officer in the 22nd century. By 2156, she served aboard the Columbia as a tactical officer.

In 2168, after the Columbia's MACOs undertook a plan to subvert the Great Work apparatus at the Caeliar city of Mantilis on Erigol, two of the MACOs managed to return to the ship. After the scattering field returned, Captain Erika Hernandez contacted the ship and revealed Major Stephen Foyle and Lieutenant Vincenzo Yacavino as mutineers. Bridge weapons officer Claudia Siguenza helped escort the two to the Brig, and Atlagic took over as her replacement. She reported that the other Caeliar city ships were not entering their subspace tunnels, but the explosion that blew apart Erigol forced the Columbia to take the chance to enter their tunnel. She, along with the rest of the crew, perished from the hyperphasic radiation inside the tunnel. (ST - Destiny novel: Gods of Night)

Columbia personnel
United Earth (civilian registry)	SS Columbia	Theodore Haskins • Vina
United Earth Starfleet	Columbia (NX-02)	Reiko Akagi • Diane Atlagic • Erika Hernandez • Trip Tucker • Karl Graylock • Veronica Fletcher • Kalil el-Rashad • Johanna Metzger • Brynn Mealia • Sidra Valerian • Kiona Thayer • Katrin Gunnarsdóttir • Biggs • Stewart Rivers • Strong • Russell Hexter • Claudia Siguenza • MACO personnel: Eric Crichlow • Stephen Foyle • Niccolo Mazzetti • Hossad Mottaki • Ndufe Otumbo • Gage Pembleton • Thom Steinhauer • Vincenzo Yacavino
Federation, Starfleet	USS Columbia (NCC-621)	Clark Terrell