Fire and Emergency Whanganui senior station officer Shane Dudley said firefighters called the security company to come and let out the people trapped in the tower.
Dunbar said two fire trucks from Whanganui Fire Station were sent to the incident.
“It was only about 15 minutes.
“Just long enough to know that someone was coming back to help them.”
Police said they attended after a report of people locked in a building on Durie Hill and referred any further queries to the Whanganui District Council.
A sign at the entrance to the tower says “This tower will be closed at dusk every day. When the hooter is sounded, please vacate immediately”.
The council, which is responsible for the tower, has been contacted for comment.
Eva de Jong is a reporter for the Whanganui Chronicle covering health stories and general news. She began as a reporter in 2023.