Investigators continue to look into the cause of Wednesday’s plane crash on Prince of Wales Island, which injured the four men on board, three seriously. Alaska State Troopers have identified the victims from the crash near Lake Galea.

Clint Johnson, senior air safety investigator with the National Transportation Safety Board, told KRBD that the pilot sent out a distress signal between 11:30 a.m. and noon. The plane crashed shortly before the pilot attempted an emergency landing in the lake.

Johnson says not much else is known at this point about the cause of the crash.

“All we know right now is that it started with a partial loss of engine power, but beyond that we don’t know exactly how the whole thing came together,” Johnson says. “That’s obviously what we’re going to be looking at during the investigation.”

The chartered flight, which was operated by Promech Air of Ketchikan, was on its way to Shipley Bay on Kosciusko Island. The de Havilland Beaver was piloted by Charlie Kenlin of Florida. The passengers, all from Washington, were identified by Alaska State Troopers as Martin and Michael Lakey, along with Rich Webster.

The Coast Guard rescue operation was coordinated by Air Station Sitka, which made two helicopter trips to evacuate the pilot and passengers. The Klawock Volunteer Fire Department aided in the operation; the fireman in charge of that rescue crew confirmed to KRBD that the crash site was inaccessible by road. He also says that Promech Air sent another floatplane to aid in the operation.

Alaska State Troopers Spokeswoman Megan Peters says that agency cooperation is normal when responding to emergencies in Alaska’s rugged terrain.

“It’s not uncommon for us to work with other agencies in order to help people in the backcountry of Alaska, whether it’s the Coast Guard, the Rescue Coordination Center, Civil Air Patrol,” says Peters. “Alaska is a really small community when it comes to search and rescues and going out and getting the people that need help.”

The Ketchikan Medical Center did not return a call seeking comment on the status of the crash victims.

A representative from the Coast Guard’s Air Station Sitka said that the crew involved with the rescue spent the night in Ketchikan. They were on their way back to Sitka Thursday.