Colton Miersma was a Terran Dominion military liason. He was scheduled to drive Commander Bartlett to the Simonson Munitions Factory where Bartlett would review the then-secret thor.
Miersma underwent a night of heavy drinking at an Augustgrad bar. The bartender, actually a Umojan shadowguard named Pandora, poisoned him. Miersma died of a sudden heart attack.
His replacement was Rebecca Schafer, who was also killed by Pandora (who then took her place). Pandora drove Bartlett to the facility and gained crucial information about the thor.