The 13-year-old boy was with a group of teens swimming in the Anacortes lake around 5 p.m. when he began to flounder, according to Capt. Lou D'Amelio with Anacortes police.
Other members of the group tried to help the boy, but he slipped under the water and they lost track of him.
The teens yelled for help and two nearby adults in the parking lot ran and jumped into the water. They eventually found the submerged teen and pulled him to shore, D'Amelio said.
The adults began CPR until an Anacortes police officer arrived and took over. Medics arrived and continued CPR as the teen was transported to a local hospital, then eventually airlifted to Harborview Medical Center in Seattle.
D'Amelio says the boy remains in critical condition.