A Starfleet lieutenant left in charge of the Enterprise-D bridge in 2368, who is killed when a quantum filament strikes the ship, leaving Counsellor Troi as the senior officer present.
Lieutenant Monroe is a bridge officer aboard the USS Enterprise-D. She appears in the episode Disaster.
During a quiet spell Captain Picard leaves the bridge to show three young science fair winners around the ship, and Monroe is the officer on duty. When the Enterprise runs into a quantum filament, power fails throughout the ship and a console on the bridge explodes. Monroe is killed.
Her death drives one of the main threads of the story. With the bridge cut off and no command officer left alive there, the highest rank belongs to Deanna Troi, a lieutenant commander with no command training. Troi has to take charge, with Miles O'Brien and Ensign Ro Laren giving her sharply different advice about whether to separate the saucer.