Thunder win coveted tournament on the diamond May 2, 2017 5:51 pm Photo courtesy of Lisa Beebe The Mercer Island Thunder 12U baseball team captured first place at the MayDay Mayhem baseball tournament on April 22 in Yakima. The Thunder went 6-0 at the tournament and defeated West Valley 6-2 in the championship game. The Mercer Island Thunder 12U baseball team captured first place at the MayDay Mayhem baseball tournament on April 22 in Yakima. The Thunder went 6-0 at the tournament and defeated West Valley 6-2 in the championship game.