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.