High winds are tonight threatening to bring down Lyttelton's historic Timeball Station which was badly damaged in Christchurch's earthquake last week.
Lyttelton fire chief Mark Buckley said one property had been evacuated and a cordon had been put up in part of nearby Reserve Terrace, Stuff.co.nz reported.
Engineers were assessing the building but it would not be demolished at this stage, Mr Buckley said.
Last Tuesday's magnitude 6.3 quake caused significant damage to the Timeball Station, already damaged by September's 7.1 quake.
The Timeball Station was built in 1876 and was one of only five remaining timeball stations in working order in the world until Tuesday's quake.
Its flags were used to communicate shipping advice to the town and its ball slowly dropped to signal the time to ships in the harbour.
Last February, fireman Dave Simpson used the flags to spell out a proposal to his girlfriend Sal.
The couple lived on the hillside beside the station and Mr Simpson said the Timeball was part of their Lyttelton life.
His romantic gesture won `proposal of the year' from a national bridal magazine.
"It was a big part of our view and a part of our Lyttelton. I can't believe it might be gone. We are gutted. It's one of the buildings around here that we identify with and the owners helped me a lot with the proposal," Mr Simpson told NZPA.
When Tuesday's quake hit the city, Mr Simpson was in the Art Gallery in the CBD while wife Sal was working at the Lyttelton Coffee Company. With no way of getting in touch with her, Mr Simpson ran, skated and hitchhiked over the hill to make sure she was alright.
"There were five or six other people doing the same thing, we had no other way of checking on people here. I didn't know she was okay and I was absolutely terrified that she wasn't."
The couple's house is still liveable and they plan to stay in the town despite the damage done.
"It is all smashed up and we are isolated here but we stick together and that's what I love about Lyttelton," he said.
The Timeball is currently cordoned off and a decision will be made on its future after it has been thoroughly inspected.