Boaters help rescue 4 people after Kenmore Air plane crashes in San Juan Islands

BELLINGHAM, Wash. -- Good Samaritan boaters rescued four people after a plane crash near the south end of Lopez Island.

The U.S. Coast Guard received an emergency electronic signal at 9:13 a.m. Friday from a Kenmore Air plane. At the same time, watchstanders also received a mayday call from the vessel Northern Rose reporting the plane crash.

The crew of the Northern Rose rescued three men and one woman from the water as the plane sank.

"I spotted four yellow objects in the water, then we realized what we were looking at,” the Good Samaritan told Q13 FOX News. “We came to a stop and they shouted that their plane had crashed and they were really cold.”

Survivors were transferred to medical staff around 9:45 a.m. at Friday Harbor. At least two of them were airlifted to Harborview Medical Center in Seattle.

All four were being treated for minor injuries and hypothermia, the Coast Guard said.

Crews from the Cutter Henry Blake and Bellingham Coast Guard station were headed to the site of the crash to mitigate the pollution threat. It's unclear if the plane will be able to be salvaged.