SEATTLE - A man who was injured when he plunged 35 feet in a stairwell at Qwest Field after Sunday's Seahawks game was identified Monday as a Portland, Ore. firefighter.

Portland Fire & Rescue Lt. Al Oswalt said the Nathan Sullivan was attending the game with at least four other firefighters Sunday.

Medics responded to the scene at about 5 p.m. and transported Sullivan to Harborview Medical Center.

Witnesses said the man was hooked to an intravenous tube and a respirator as medics rushed him into the ambulance. On Monday afternoon, Sullivan was listed in serious condition at Harborview.

The accident happened after the Seahawks lost to the Philadelphia Eagles in Sunday's NFL game. It was not clear what Sullivan was doing at the time or what caused him to fall.

Oswalt said Sullivan has been with Portland Fire & Rescue for 5 ½ years and is a member of the department's specialty rescue team, which conducts high-angle, cliff, dive and trench rescues.