FRIDAY HARBOR, Wash. -- Deputies from the San Juan Island Sheriff's Office are investigating a reported murder-suicide on board a boat.

Sheriff Bill Cumming told KIRO 7 Eyewitness News Wednesday night that his department got a call from the police department in Bellevue, Wash. Bellevue police said friends of a man reported they received texts from him saying he had killed his girlfriend, and was planning to kill himself.

Bellevue police "pinged" the man's cell phone and had an approximate location of San Juan Island.

A boat with the United States Coast Guard located the man's boat as it left Friday Harbor on San Juan Island and followed it to the west side of nearby Orcas Island.

As the Coast Guard approached the boat, the man ran below deck, despite being ordered to stay topside.

A shot was heard by the Coast Guard officials, who jumped onboard and found the man still alive but seriously wounded.

Medics with the Coast Guard performed CPR but he was pronounced dead at the scene.

The San Juan County Sheriff's Office arrived and found both the man and a woman dead on board the powerboat.

The woman appears to have died earlier in the day.

The boat has been towed to Friday Harbor. It will be searched by police once a search warrant is cleared.

Both the man and woman's bodies were taken to the Snohomish County Medical Examiner's Office in Everett for autopsies.

No names have been released.