While working maintenance on Babylon 5 in late 2258, Nolan, a member of the radial pro-Earth group Homeguard, was assigned to plant a bomb in one of the station's Cobra Bays. The bomb was supposed to detonate upon the arrival of Earth Alliance President Luis Santiago. Inexperienced with such devices, Nolan accidentally detonated the bomb while he was setting it up, critically injuring himself in the process. He was rushed to Medlab where his diagnosis looked bleak.
Against Dr. Stephen Franklin's orders, Maj. Lianna Kemmer, head of the President's security detail, revived Nolan to question him about the bombing. Nolan died within minutes after being revived, but not before confirming it was a bomb and falsely implicating Security Chief Michael Garibaldi, who had previously arrested Nolan for trashing an alien shop on the station.