The incident happened just after 1 p.m. at the staircase near Jefferson and 19th, fire officials said. The motorhome went over the sidewalk, hit the concrete barriers and went down the stairwell at the center of the campus, said Loretta Cool with the Tacoma Police Department.
Witnesses described a chaotic scene.
"I saw a flash and saw a motorhome slam right into the planter box and fly down the stairs and disintegrated," said Jack McQuade, owner of the nearby Swiss Restaurant and Pub. "It looked like it was in a movie, just dirt and debris went everywhere."
The 65-year-old woman driving the 18-foot motorhome was pronounced dead at the scene. Cool said preliminary investigation shows the woman was ejected from the motorhome and then was crushed as it continued rolling.
No pedestrians were struck and there were no other injuries, fire officials said.
Cool says investigators are looking at a mechanical failure as the cause of the crash.
"It appears she was having some mechanical difficulties in the car that possibly caused the brakes to fail," Cool said.
The victim's name has not been released pending notification of family members.
Cool says the university is offering counseling services to anyone who witnessed the accident.