A slip has closed the Durie Hill Elevator.
Debris from it spilled across the pathway at the opening of the elevator's entrance tunnel last week.
Engineers have been on site to assess the situation, a Whanganui District Council spokesperson said, and it is possible that more earth will fall.
"In the meantime, to keep everyone safe the elevator will be closed while we work on a fix."
The elevator's operator Anthonie Tonnon from Whanganui Connection said he hoped it would reopen soon.
The team had four and a half months without a full day's closure during the summer, Tonnon said.
"Consistency has been the theme of the summer for us, and that's been translating to growing local patronage."
The elevator's usual hours are 8am to 6pm Monday to Friday, and 10am to 5pm on Saturdays, Sundays and public holidays.