One person was killed and three were injured by a landslide that prompted a mandatory evacuation in the Alaska city of Ketchikan, authorities said.

Three people were transported to Ketchikan Medical Center following the landslide, which struck around 4 p.m. Sunday and damaged homes and infrastructure, the Ketchikan Gateway Borough and City of Ketchikan said in a joint statement Sunday.

Alaska Gov. Mike Dunleavy declared an emergency for Ketchikan, while Borough Mayor Rodney Dial and city Mayor Dave Kiffer issued a separate emergency declaration.

“Friends, is with a heavy heart we relay that a landslide in the city has taken a life, caused several injuries, damaged homes and impacted our community,” Dial said in the statement.

Kiffer said the loss of life was “heartbreaking, and my heart goes out to those who lost their homes.”

“In my 65 years in Ketchikan, I have never seen a slide of this magnitude. With the slides we have seen across the region, there is clearly a region-wide issue that we need to try to understand with the support of our State geologist,” Kiffer said.

Two of the victims were admitted to the hospital and one was treated and released. All other individuals have been accounted for, the statement said.

Multiple homes were impacted by the landslide and a mandatory evacuation was ordered for residents of Third Avenue and nearby streets, while a shelter was set up at Ketchikan High School, the borough and city said.

A potential secondary landslide area was identified to the south of the original slide location and crews were standing by, the statement said.

Power was restored to some affected areas by 8:15 p.m. Other areas will remain without power while the landslide is cleared and broken power poles are replaced, the borough and city said.

Various local and state agencies responded to the landslide in the southeastern Alaska city located about 297 miles (478 kilometers) south of Juneau, the state capital.

A Department of Homeland Security and Emergency Management Response Specialist and federal Department of Transportation personnel are expected to travel to Ketchikan on Monday, Dunleavy said.

“I have directed state agencies to make available all resources and staff for the response effort,” Dunleavy said, noting the city was receiving assistance from the State Emergency Operations Center.

The landslide followed a weekend bout of rain amid an abnormally dry August for the region, said Andrew Park, a meteorologist in Juneau with the National Weather Service. The heaviest rainfall came overnight Saturday and moved south through the Ketchikan area on Sunday.

The event occurred absent of some of the red flags meteorologists typically look for, such as high winds, Park said.

“There weren’t any of the big red flags we would normally see,” said Park, although he said landslides can be relatively unpredictable.

He said the region seeing landslides of different magnitudes isn’t rare, even on dry days, but “we don’t really see the impacts” because the population density is so small.

“If you ever fly over the panhandle and you look down, you can see landslide scars all over the place — massive landslide scars,” he said. “In terms of, is it unsual for it to impact our cities? Very. This is a very unusual event. But landslides are not unusual to our region.”

Landslides tend to garner little notice when they strike in remote, unpopulated areas, but they also have the potential to cause immense catastrophes. As climate change intensifies storms and wildfires, destabilizing soil, the risk increases.

Landslides include debris flows often triggered by heavy rains. When logging or fire destroys trees, the loss of root structure can weaken soil. Rain that isn’t being sucked up by plants can saturate the ground, making it more likely to slide. Other types include creeps, which move slowly downward, and rock falls.

In Alaska, melting permafrost, retreating glaciers, earthquakes and pounding rains can trigger landslides.

(AP)