The pilot of a helicopter that crashed into a Snohomish County lake has died, according to a family friend. The pilot and his passenger were rescued after the chopper lost altitude soon after taking off Tuesday afternoon and plunged into King Lake, about five miles southwest of Arlington. The passenger was swimming toward a log after the crash and was pulled from the water by a local resident with a boat. The pilot was found floating face-down in the water. Both were taken to a local hospital, where the passenger was listed in serious condition and the pilot was listed in critical condition.