Grant County Sheriff's Office is investigating the possible drowning last Saturday at Alkali Lake just north of Soap Lake.

On July 16, around 5:30 p.m., authorities were notified that a man in his 60s swam to an island 25 feet away and 100 feet away from the mainland.

When he tried to swim back, he went under the water and did not resurface.

Rescue crews were on the scene until dark to look for the man's body and resumed their search the following morning on July 17.

Public Information Officer Kyle Foreman says they will continue searching until his body is found.

The Columbia Basin Dive Rescue Crew came out from Tri-Cities to aid the search.