The slip hit the Howden Hut at 1.30am, leaving two people with minor injuries.
A rescue operation of a total of 100 people on walking tracks is underway this morning with helicopters lifting off to take advantage of a break in the weather.
Emergency Management Southland controller Angus McKay said pilots were in the air this morning evacuating people from huts in Hollyford, Pyke, Big Bay and Martin’s Bay.
Thirty-one people from the Howden Hut on the Routeburn Track were safe after a landslide hit the hut at 1.30am this morning.
Two people suffered minor injuries, which were treated by a doctor on site.
A state of emergency was declared in the area yesterday afternoon as heavy rain and slips trapped 100 tourists on tracks and roads, stranded others in accommodation at Milford Sound, and closed State Highway 94, the only road into Milford Sound.
MetService forecaster Lewis Ferris said one metre of rain had fallen in 60 hours in Milford Sound, and 600mm of that was in the 24 hours to about 7am today.
"Those are numbers some of our most experienced forecasters haven't seen before," Ferris said.
"So 1000mm in an entire event has been seen before, but to get that in two-and-a-half days has been quite a lot."
Mr McKay said those inside Howden Hut were safe and awaiting evacuation.
A doctor in the hut looked after "a couple of people" who had been injured, McKay said.
The track is extensively damaged and flooded around the hut so walking out was not an option for anyone on the Routeburn or Hollyford track, McKay said.
The 195 tourists in lodges in the Milford Sound area, where 200 hotel and lodge staff are also stranded, may be stuck there for another day.
"They're warm and accommodated and being fed so they're not really our top priority, it's really the people out on the eastern side of the Homer Tunnel who we need to get down from these huts and lodges," McKay said. The 100 people still stranded were on the tracks, the road and on the coast at Martins Bay and Big Bay.
"The forecast keeps changing - we might have a window later on this morning but then the rain comes back down - and we're actually seeing the rest of the region getting some flooding on the roads."
MetService issued a red warning for Westland south of Hokitika and Fiordland north of George Sound. A red warning means the the effects would be significant and immediate action is needed to protect people and property.
Additional reporting ODT
