MADISON -- The family of a windsurfer killed on Lake Mendota in Madison has retained a lawyer.
43-year-old Yu Chen was killed after he was struck by a UW life-saving boat.
The attorney says crucial evidence is being withheld by the Wisconsin Department of Natural Resources and the Dane County Sheriff's Office.
He claims the boat struck Chen from behind and knocked him into the lake, where his body was chopped by the propellers until he died.
The family is seeking video surveillance footage from all available cameras, including those at the governor's executive residence on the lake.