Abstract: At approximately 11:00 a.m. on April 23, 2004, Employee #1 accompanied the contracted diver, owner of Hegi Enterprises, on a dive to clean the aerating equipment located at the bottom of Vadnais Lake. The work consisted of diving approximately 60 ft down and removing and cleaning the aeration heads on the lake aerator. Employee #1 was attending on the dive for the purpose of possibly bidding on the job. The owner of Hegi Enterprises accompanied for the purpose of showing Employee #1 the procedure. Employee #1 had his own dive company, 35 Fathoms Inc., and was interested in replacing the soon to retire owner of Hegi Enterprises. After nearly completing the cleaning and replacing of the Aeration heads, the Hegi diver signaled to Employee #1 to surface. Employee #1 responded that he would surface. The owner of Hegi Enterprises began to surface and returned moments later to check if Employee #1 had left the area. After returning to the work area, below the Aerator unit, he did not view Employee #1 in the area. The Hegi owner surfaced and asked his daughter, in the assist boat, if she had seen Employee #1. Employee #1 had not surfaced. A return dive was made with visual contact made with Employee #1 who was apparently unconscious and above the work area at the bottom of the aeration unit. After an attempt was made to remove Employee #1, the diver returned to the surface and had his daughter call emergency medical services for assistance. The Sheriff rescue personnel entered the lake and removed Employee #1 who had deceased. No definitive cause of death was determined by the Medical Examiner. The Ramsey County Water Rescue did not determine a specific problem with the diver's equipment. Employee #1 was not an employee of the St Paul Water Treatment Facility, and was not employed by the contracted diver, Owner of Hegi Enterprises.