A 47-year-old man is dead after police say he drowned at Luther Burbank Park while paddleboarding on Sunday.

At about 5 p.m. on July 21, Mercer Island Police and Fire personnel responded to a possible drowning just offshore of the park in the 2400 block of 84th Avenue Southeast. Police said the drowning location was outside and north of the swim beach area — about 30 to 50 yards offshore.

When first responders arrived, they determined that the man was paddle boarding in Lake Washington and fell off the board into the water. He was not wearing a life jacket, police said.

An effort to save the man was made by bystanders who swam out to assist. But their efforts were to no avail.

Mercer Island Police and Fire Dive Team, Renton Fire and the King County Sheriff’s Office Dive Team all began a search effort to locate the man. About one hour later, the man was recovered and in about 17 feet of water.

Bellevue paramedics made lifesaving efforts but the man was pronounced dead at the scene. The King County Medical Examiner’s Office will determine the cause and manner of death.