An Iowa State student was assaulted Thursday night as she was climbing the stairs to the terrace on the west side of the Memorial Union, Department of Public Safety officials said.

DPS officers responding to a 911 call found the woman unconscious in the hallway of eighth floor of Larch Hall at about 10:23 p.m. on Thursday.

The woman, a Larch resident, had a bump on her head and was transported to Mary Greeley Medical Center, where she was treated and released.

The woman told DPS officers the attack had occurred nearly two hours earlier, at about 8:30 p.m.

Loras Jaeger, director of DPS, said the student was walking across campus and had come to the stairs on the west side of the MU.

She then began to climb the stairs to the terrace when an unknown assailant grabbed her coat from behind, pulling her down to the bottom of the stairs.

The attacker, who was only identified as a white male, then attempted to pull the woman up into the air before dropping her and fleeing the scene.

The woman told DPS officers she thought an individual in the area scared off the attacker.

The victim then returned to her residence, where she fell unconscious.

Jaeger said there were no suspects yet in the case and no motives for the attack had been produced. The investigation is ongoing.